Vendor due diligence is the seller running the buyer’s due diligence exercise on its own business, before the business goes to market. On a large deal that means commissioning an independent report that a buyer can rely on. On an owner-managed business sale it means something more useful and much cheaper: finding and fixing the legal defects a buyer’s solicitors will otherwise find for you, at a point when they still cost only time.
The distinction matters because the two things are usually written about as if they were the same. Search for vendor due diligence and you will mostly find corporate finance firms describing a paid financial report produced for private equity exits and competitive auction processes. That is a real service, and on the right deal it earns its fee. It is not what most sellers of a trading company with a few million pounds of turnover actually need, and it does nothing about the problems that genuinely derail SME sales, which are almost never financial.
The problems are legal housekeeping, and they are remarkably consistent: a register of members that nobody has updated since 2014, a share certificate that cannot be found, three of the five largest customer contracts unsigned, a lease that needs the landlord’s consent, and no written assignment from the freelancer who built the website. None of these is difficult to fix. All of them are expensive to fix once a buyer has found them.
This article sets out what vendor due diligence means for an SME seller, why the timing of a discovery changes its price, and a workstream by workstream checklist of the legal preparation to do before you go to market. It sits alongside our wider guide to selling a business in the UK.
What vendor due diligence actually means
Due diligence on a company sale is the buyer’s investigation of what it is buying. The buyer’s solicitors issue a questionnaire, the seller answers it in writing, documents go into a data room, and the buyer’s advisers report on what they find. We set out that process from the buyer’s side in our guide to legal due diligence when buying a business.
Vendor due diligence reverses the direction of travel. The seller runs the same investigation on itself, in advance, and does something about the answers. There are three distinct versions of it, and conflating them is where most of the confusion comes from.
The formal vendor due diligence report
On larger transactions, and particularly where the seller is running an auction with several bidders, the seller commissions independent accountants or lawyers to produce a full due diligence report before the process begins. The report is addressed to the seller, then made available to bidders, usually with a reliance letter allowing the eventual buyer to rely on it and sue the author if it is wrong.
This has real advantages on the right deal. It levels the information available to every bidder, it stops five sets of advisers asking management the same questions for three months, and it preserves competitive tension by shortening the exclusivity a buyer needs. It also costs a substantial professional fee and takes a couple of months, and the reliance letter is itself a negotiation.
It is proportionate where there are multiple credible bidders, where management time is genuinely the scarce resource, or where a private equity seller needs a tightly controlled process. On a single-buyer sale of an owner-managed company it is usually not proportionate, because there is no competitive tension to preserve and only one set of advisers to satisfy.
Vendor assistance
A lighter version, where advisers help the seller prepare the data room, anticipate the questions and draft the answers, without producing a report anyone relies on. This is a sensible middle ground and is often what a seller actually wants when they ask about vendor due diligence.
Legal preparation, which is what most SME sellers need
The version that matters most, and the one that is written about least, is simply doing the legal housekeeping. You take the questionnaire a buyer’s solicitor would send, work through it against your own records, and fix what is wrong. No report is produced and nobody relies on anything. The output is a business whose paperwork survives inspection.
This is the version that protects the price, because it addresses the defects that cause price reductions rather than the financial information a buyer would re-analyse anyway. It is also the version a seller can start without instructing anybody, which is why we put it at the front of any conversation with a client about preparing a company for sale.
Why a problem found early costs only time
The reason to do this before marketing rather than during diligence is not tidiness. It is that the identical defect has a completely different price depending on who finds it.
When you find it, the question is how to fix it. When the buyer finds it, the question is who bears the risk, and that question is answered in a document the buyer’s solicitors are drafting. The usual answers are a reduction in the headline price, a retention from the consideration held back for a year or more, money held in escrow, or a specific indemnity under which you pay pound for pound for the consequences, often without the cap and time limit that apply to the general warranties.

| Found by you, before marketing | Found by the buyer, in due diligence | |
|---|---|---|
| Who controls the timing | You do. The problem is found months before a buyer is in the room, and you choose when and how it is fixed. | The buyer does. It is raised mid-process, when you have already told staff, advisers and possibly customers that a sale is happening. |
| What it costs | Time and professional fees to put the paperwork right. The price is unaffected because the defect is gone before anyone values the business. | A price reduction, a retention from the consideration, an escrow account, or a specific indemnity with no cap and no time limit. |
| Effect on the warranties | Nothing to disclose, because there is nothing wrong. The warranty schedule is given clean. | A disclosure against the warranty, which protects you only if the disclosure is full and fair, and often a specific indemnity on top. |
| Effect on the timetable | Absorbed into the preparation period. It does not sit on the critical path to completion. | Added to the critical path. Third party consents, landlord consent and regulator approvals cannot be accelerated by paying more. |
| Effect on negotiating position | Neutral or positive. A clean data room makes a buyer more willing to accept seller-friendly warranty limitations. | Negative, and not only on the issue found. One defect invites deeper diligence everywhere else. |
| Effect on deal certainty | No effect. The buyer never knows the problem existed. | Material. Title defects, missing IP ownership and lapsed licences are the issues that cause an SME deal to be abandoned rather than repriced. |
The last row of that table is the one sellers underestimate. Most defects found in diligence are priced rather than fatal. A handful are genuinely fatal: the company does not own the intellectual property it trades on, the registered proprietor of the premises is a dissolved company, the licence the business needs expired two years ago. Those are the issues on which buyers walk away, and they are all discoverable by the seller in advance.
There is a second-order effect too. A buyer’s solicitor who finds one significant gap in the corporate records does not assume the rest is fine. They widen the enquiry, ask for more, and recommend tighter warranty protection across the board. A clean data room buys you credibility that is worth real money when you come to negotiate warranties and indemnities.
Preparation also shortens the deal. Third party consents, landlord’s consent and regulatory approvals cannot be accelerated by paying more, and they sit squarely on the critical path. We look at what actually drives the timetable in our piece on how long it takes to sell a business.
The vendor due diligence checklist, by workstream
Below is the preparation exercise set out as a checklist. It is organised by workstream, because that is how a buyer’s solicitor will ask for it and how a data room should be indexed. Against each item is why the buyer cares, which is the part most checklists leave out, and a realistic lead time for fixing it from a standing start.
The lead times assume an owner-managed trading company and a cooperative counterparty. They are deliberately wide, because the difference between a two week fix and a sixteen week fix is usually whether a third party has to agree to something.
| Item | What to get in order before you market | Why a buyer cares | Typical lead time |
|---|---|---|---|
| A. Corporate records and constitution | |||
| Register of members | Reconstruct it from incorporation to today, naming every member, the date each was entered and removed, and the shares held. Keep it at the registered office or a single alternative inspection location. | On a share sale this is the evidence that the people signing the share purchase agreement actually own the shares being sold. A gap in it is a gap in the buyer’s title. | 2 to 8 weeks |
| Share certificates | Produce an original certificate for every current holding. Where one is lost, pass a board resolution and issue a replacement against an indemnity before you go to market. | A buyer will not release funds against a missing certificate. It is the classic item that surfaces in the final week and delays completion. | 1 to 3 weeks |
| Historic share transfers | Collect every stock transfer form, check each one was signed, and check it was stamped or carried a valid exemption certificate. | An unstamped transfer over the duty threshold leaves a defect in the chain of title and an unpaid liability the buyer will want indemnified. | 2 to 6 weeks |
| Board and shareholder resolutions | Produce signed minutes for every allotment, transfer, buyback, director appointment, dividend and change of name or articles. | A share issue without a valid allotment resolution may be challengeable. Dividends paid without distributable reserves or without resolutions are a tax and claw-back risk. | 2 to 6 weeks |
| Articles and shareholders’ agreement | Read the current articles against the share capital you actually have. Check pre-emption rights, transfer restrictions, drag-along and tag-along, and any consent required for a sale. | If a minority holder has a consent right or a pre-emption right that was never waived, the buyer cannot acquire 100 per cent without their cooperation. | 1 to 4 weeks |
| PSC information at Companies House | Check the people with significant control shown on the public register match reality, including nature of control and the correct percentage bands. | A wrong PSC entry suggests the buyer cannot rely on the register generally, and false PSC filings carry their own exposure. | 1 to 2 weeks |
| B. Companies House compliance | |||
| Identity verification | Verify the identity of every director and every PSC, obtain their personal codes and provide them to Companies House in the correct window. | A seller who has not verified cannot cleanly make the filings a completion requires, and an unverified PSC is an unresolved compliance breach sitting in the data room. | Days to 4 weeks |
| Confirmation statement | Confirm it is filed and accurate, with a registered email address and the lawful purpose statement in place. | Late or inaccurate confirmation statements are the cheapest possible signal that corporate records are not being kept properly. | 1 to 2 weeks |
| Accounts and filing history | Check every set of accounts was filed on time and that no late filing penalty is outstanding. Deal with any strike-off or proposal to strike off. | Filing history is public, free and the first thing a buyer’s solicitor looks at. It frames every assumption they make afterwards. | 2 to 8 weeks |
| Charges register | List every charge registered against the company and obtain the paperwork to release any that has in fact been repaid. | A satisfied charge still showing on the register will stop a lender funding the buyer, and releases take time to obtain. | 3 to 10 weeks |
| C. Commercial contracts | |||
| Signed copies of key contracts | Produce a signed, dated, complete copy of every contract that carries material revenue, including schedules and variations. | Revenue a buyer cannot tie to a signed contract is revenue it will discount or refuse to pay for. | 3 to 10 weeks |
| Expired and rolled-over terms | Identify contracts running past their stated end date and either renew them or document the basis on which they continue. | A customer trading on expired terms can walk away the day after completion. That hits the price directly. | 4 to 12 weeks |
| Change of control clauses | Read every material contract for a change of control, assignment or termination on sale provision, and list which need consent or notice. | These dictate whether the buyer needs third party consents before completion, which is often the single biggest driver of the timetable. | 4 to 12 weeks |
| Standard terms and conditions | Check your terms were actually incorporated into each contract, and that limitation and exclusion clauses are current. | Terms that were never incorporated leave the business exposed on liability it believed was capped. | 2 to 6 weeks |
| Supplier dependency | Identify any supplier the business cannot replace quickly, and the notice and termination terms that apply. | Concentration risk is priced. Unwritten arrangements with a critical supplier are priced harder. | 2 to 8 weeks |
| D. People | |||
| Written statements of particulars | Issue a principal statement to every employee and worker who does not have one, and bring existing statements up to date. | Missing statutory documentation is a straightforward breach the buyer will want warranted, and it suggests wider HR gaps. | 3 to 8 weeks |
| Signed contracts and variations | Produce signed contracts for every employee, plus signed records of pay rises, promotions and role changes. | Undocumented terms become the buyer’s problem, and are a common source of post-completion claims. | 4 to 10 weeks |
| Directors’ service agreements | Check whether the owner, and any family member on the payroll, has a written service agreement and what it says about notice and restrictive covenants. | A buyer wants to know what it is taking on and what the owner is restrained from doing afterwards. | 2 to 5 weeks |
| Contractor and consultant status | Review anybody paid outside the payroll against what they actually do day to day, and check the written agreement matches the reality. | Mislabelled contractors create employment, tax and holiday pay exposure, and it is exposure the buyer will want covered by a specific indemnity. | 4 to 12 weeks |
| Restrictive covenants | Check covenants exist for the people who could damage the business if they left, and that they are drafted narrowly enough to be enforceable. | Covenants that are too wide are worth nothing. A buyer paying for customer relationships wants them protected. | 3 to 8 weeks |
| Pensions and auto-enrolment | Confirm the scheme is registered, contributions are up to date and re-enrolment duties have been met. | Unpaid or under-paid contributions are a quantifiable liability with a regulator attached. | 3 to 8 weeks |
| E. Intellectual property and data | |||
| Founder and employee IP | Check whether the people who created the core IP were employees at the time, and whether their contracts contain an IP assignment. | If a founder built the product before incorporation, the company may not own it. That can be fatal to the deal rather than merely expensive. | 3 to 10 weeks |
| Freelancer and agency IP | Obtain written assignments from every freelancer, developer, designer and agency who created material the business relies on. | Without a signed written assignment the copyright stays with the creator, whatever the invoice says. | 4 to 16 weeks |
| Trade marks and domains | Check registrations are in the company’s name, in force, and cover the classes and territories actually used. Check domains and social accounts are held by the company, not an employee. | Marks held personally, or domains registered to a former developer, have to be transferred before completion. | 3 to 12 weeks |
| Software licences | Audit licences for the software the business runs on, including user counts and whether the licence survives a change of control. | Under-licensing is a quantified liability. A licence that terminates on sale is a transaction blocker. | 3 to 8 weeks |
| Data protection records | Produce your record of processing activities, privacy notices, data processing agreements with suppliers, retention policy and breach log. | A buyer wants to see the records before it warrants compliance. The absence of a record of processing is itself the breach. | 4 to 10 weeks |
| F. Property and premises | |||
| Freehold title | Obtain official copies of the register and title plan, and check the registered proprietor is the company and the plan matches what you occupy. | Title defects, missing rights of way and unregistered extensions take months to resolve and cannot be rushed at completion. | 4 to 16 weeks |
| Leases | Produce the lease, every licence and deed of variation, the rent deposit deed, and evidence that rent reviews were documented. | A buyer is taking on the lease liability. Gaps in the lease paperwork are gaps in what it can price. | 3 to 10 weeks |
| Landlord’s consent | Identify whether the lease needs consent to assign or contains a change of control provision, and approach the landlord early. | Landlord consent is outside your control and routinely sets the completion date on a deal involving leasehold premises. | 6 to 16 weeks |
| Alterations and compliance | Collect licences for alterations, planning consents, building regulations approvals, EPCs, fire risk assessments and asbestos surveys. | Unconsented alterations are a reinstatement liability at lease end, which the buyer will deduct or require covered. | 4 to 12 weeks |
| G. Regulatory, disputes and insurance | |||
| Licences and registrations | List every licence, permit, approval and registration the business needs to trade, with the holder, expiry date and renewal position. | A licence held by the wrong entity, or lapsed, may stop the business trading on day one under the buyer’s ownership. | 4 to 20 weeks |
| Sector regulator position | Obtain your current regulatory ratings, inspection reports, open actions and any enforcement correspondence. | In a regulated sector the regulator’s timetable, not the lawyers’, sets the completion date. | 6 to 24 weeks |
| Litigation and threatened claims | Prepare a schedule of every live claim, tribunal case, debt recovery action, formal complaint and threatened claim, with status and estimated exposure. | A claim disclosed early is a negotiated allocation of risk. The same claim found by the buyer is a retention or an indemnity on the buyer’s terms. | 2 to 6 weeks |
| Insurance | Produce current policies, the claims history for the last six years, and check cover limits against the contracts you have signed. | A buyer checks whether you carry the cover your customer contracts require. A gap is an uninsured liability it is inheriting. | 2 to 5 weeks |
| Tax compliance | Confirm returns are filed and payments up to date across corporation tax, VAT, PAYE and any employment related securities reporting. | Tax is covered by its own indemnity in most share purchase agreements. Clean records narrow what the buyer asks for. | 4 to 12 weeks |
Not every row applies to every business. The point of working through it in full is that you find out which rows apply to yours before somebody else does. The sections that follow deal with the items we see cause the most trouble on owner-managed sales.
Corporate records: the register of members is the one that still matters
Every company must keep a register of its members under section 113 of the Companies Act 2006, and under section 127 that register is prima facie evidence of the matters the Act requires to be entered in it. On a share sale it is therefore the document that proves the people signing the share purchase agreement own the shares they are selling. A buyer’s solicitor will ask for it in the first week.
In practice this is the single most commonly neglected document in an owner-managed company. Shares are issued, transferred, gifted to a spouse or bought back over fifteen years, and the register is written up for none of it. Reconstructing it afterwards means working backwards through Companies House filings, bank records, old accountants’ files and whatever minutes survive, and it can take weeks.
What changed on 18 November 2025
There is a point of genuine currency here that most content on preparing a business for sale has not caught up with. From 18 November 2025, companies no longer have to keep their own registers of directors, directors’ residential addresses, secretaries or people with significant control. That information is held at Companies House instead, and companies must keep it up to date there.
The register of members is the exception. It must still be kept, either at the registered office or at a single alternative inspection location, and it must still be available for public inspection. Companies that previously kept their members’ information centrally at Companies House must create and maintain a full register of members.
For a seller this simplifies the exercise and sharpens it at the same time. There are fewer local registers to produce, but there is now nowhere to hide on the one that counts. If your statutory book folder contains four immaculate registers and a members’ register that stops in 2014, you have prepared the wrong thing.
Share certificates and the chain of title
A buyer will not release the consideration against a missing share certificate. Where an original cannot be found, the usual route is a board resolution noting the loss and the issue of a replacement certificate against an indemnity from the holder. That is a straightforward piece of work, and it is a straightforward piece of work that takes a fortnight you will not have in the final week before completion.
The chain of title also needs checking for stamping. Stamp Duty on a transfer of shares using a stock transfer form is charged at 0.5 per cent of the consideration, rounded up to the nearest £5, where the consideration is more than £1,000. The form must be sent to HMRC and the duty paid within 30 days of the form being signed and dated. An unstamped historic transfer that should have been stamped leaves both a defect in the chain of title and an unpaid liability, and a buyer will want it dealt with or indemnified.
Transfers of £1,000 or less, where the transfer is not part of a larger transaction or series of transactions, do not need to be sent to HMRC at all, which is why many small family transfers are correctly unstamped. The problem is the transfers that fall the other side of the line and were treated the same way. Confirm your own stamp duty position with your accountant or tax adviser before you rely on it.
Resolutions and the constitution
Produce signed minutes for every allotment, transfer, buyback, dividend, director appointment and change to the articles. An allotment made without a valid resolution, or a buyback carried out without following the statutory procedure, can be challengeable, and a buyer acquiring 100 per cent of a company wants to know that 100 per cent is what exists.
Then read the articles and any shareholders’ agreement against the share capital you actually have. Pre-emption rights on transfer, consent rights held by a minority holder, and drag-along provisions all determine whether you can deliver the whole company to a buyer. A minority holder with an unwaived pre-emption right is not an obstacle you want to discover after heads of terms are signed, which is one reason we recommend reading the constitution before you negotiate heads of terms.
Companies House: filings and the identity verification deadline
Filing history is public, free and instantaneous, and it is the first thing a buyer’s solicitor looks at. Late accounts, a proposal to strike off, or a confirmation statement filed eight months late all set the tone before anyone opens the data room.
Late filing penalties for a private company or LLP run from £150 where accounts are up to one month late, to £375 for up to three months, £750 for up to six months and £1,500 beyond that, and the penalty is doubled where accounts are filed late in two successive financial years. Failing to file accounts or confirmation statements is also a criminal offence for which directors can be personally fined, and the registrar can take steps to strike the company off.
Identity verification, and why October 2026 is the moment to act
Identity verification at Companies House became a legal requirement on 18 November 2025, with a twelve month transition period for existing directors and people with significant control. That transition closes in mid-November 2026, which is a matter of weeks from now, and any seller planning a sale in the next eighteen months should treat it as part of their preparation rather than as a separate compliance chore.
The mechanics differ depending on the role, and this catches people out:
- An individual verifies their identity either directly through GOV.UK One Login or through an Authorised Corporate Service Provider, and receives a Companies House personal code.
- A new director provides the personal code as part of the incorporation or appointment filing.
- An existing director provides it as part of the company’s next confirmation statement.
- A person with significant control who is also a director must do it twice: once as a director with the confirmation statement, and again through the PSC verification service within a fourteen day period starting the day after the company’s confirmation statement date.
- A person with significant control who is not a director must provide their code within the first fourteen days of their birth month.
- A person added as a PSC on or after 18 November 2025 provides their code when first added to the register, or within fourteen days of being added.
Failing to comply as a PSC may be an offence carrying a financial penalty or fine, and Companies House has said it may in future display a note against the individual’s name on the public register. A note of that kind sitting against the seller’s name during a sale process is exactly the sort of thing a buyer’s solicitor reports on.
Identity verification for people who file documents at Companies House is coming later, no earlier than November 2027, with at least six months’ notice. Corporate directors, corporate PSCs, corporate LLP members and limited partnerships are also subject to later implementation dates. Separately, all accounts filings made on or after 1 April 2028 must be made using commercial software in iXBRL format, with the web and paper routes closing for accounts. That is beyond most current sale timetables, but it is worth knowing if your deal involves a deferred element that keeps you connected to the company.
Two other items frequently need picking up at the same time. Every company must now have a registered email address, provided on incorporation for companies formed from 4 March 2024 and with the next confirmation statement for existing companies with a statement date from 5 March 2024 onwards. Every confirmation statement with a statement date from 5 March 2024 onwards must also carry a statement confirming that the company’s intended future activities are lawful.
Customer and supplier contracts
Contracts are where vendor due diligence earns its keep, because the work is slow, entirely within your control, and directly tied to what the buyer is paying for.
Unsigned and expired
Start with the contracts that carry material revenue and ask a blunt question of each: is there a signed, dated, complete copy, including the schedules and every variation? Revenue that cannot be tied to a signed contract is revenue a buyer will discount, because it cannot be sure the terms are what you say they are or that the customer is committed at all.
Then look at end dates. Contracts running months or years past their stated expiry, on an unwritten understanding that everyone is happy, are common in owner-managed businesses and a genuine valuation problem. A customer trading on expired terms owes you nothing after completion. Renewing those contracts, or at least documenting the basis on which they continue, is the single highest-value piece of preparation most sellers can do.
Chasing a counterparty for a signature takes as long as the counterparty takes. Four to twelve weeks is realistic across a portfolio, longer where the customer is a large organisation with its own procurement process. Start early, and resist the temptation to tell the customer why.
Change of control clauses
Read every material contract for a change of control, assignment or termination on sale provision. These clauses determine the shape of the transaction, because they tell you which third parties have to agree to something before you can complete.
A change of control clause typically allows the counterparty to terminate, or requires their consent, when the ownership of the contracting company changes. They are common in supply agreements, franchise agreements, distribution agreements, finance documents, software licences and leases. A seller who knows which contracts contain one can plan the consent process. A seller who does not will have the buyer’s solicitors tell them, at which point the consents become a condition of completion on the buyer’s timetable.
Share sale or asset sale changes the problem
Which transaction structure you use changes the contractual position entirely, and we compare the two in detail in our guide to share sales and asset sales.
On a share sale the company itself does not change, so its contracts continue without needing to be transferred. The exposure is concentrated in change of control clauses. On an asset sale the buyer takes a different legal entity, so each contract has to be assigned or novated, which means the counterparty’s involvement in every case rather than only where a clause requires it. An asset sale therefore generates far more third party consent work, and that work is the main reason asset sales of trading businesses take longer than sellers expect.
Our commercial contracts team reviews contract portfolios ahead of a sale precisely to produce this list, because it is the document that lets you plan a realistic timetable.
Employment contracts and contractor status
Employment is the workstream where the paperwork gap is widest in owner-managed businesses, and the one where the liability is easiest for a buyer to quantify.
Written statements of particulars
An employer must give employees and workers a written statement of the main conditions of employment. The principal statement must be provided on the first day of employment, with a wider written statement within two months of the start of employment, and employees or workers must be told about any change to the written statement within one month of the change being made.
The principal statement must cover, as a minimum, the employer’s name, the individual’s name, job title or description of work and start date, how much and how often they will be paid, hours and days of work and whether and how these may vary, holiday entitlement, where they will work and whether they may have to relocate, how long the job is expected to last, the length and conditions of any probationary period, any other benefits, and any obligatory training. Information about sick pay and procedures, other paid leave and notice periods must also be given on the first day, either in the principal statement or in a separate document the individual has reasonable access to.
Missing statutory documentation is a straightforward breach, easy for a buyer to identify and easy to quantify. It also raises a broader inference about how the business is run. Issuing statements to the people who do not have one, and bringing existing statements into line with what people are actually paid and actually do, takes weeks rather than months and removes a whole category of warranty negotiation.
Undocumented variations
The related problem is the pay rise, promotion or change of hours agreed verbally and never recorded. Over a decade this produces a workforce whose real terms differ from their written terms. The buyer inherits the real terms and warrants against the written ones, so the gap becomes a disclosure at best and a claim at worst. Document the variations now, with the employee’s agreement.
Contractor and consultant status
Anybody paid outside the payroll needs looking at properly. Employment status is determined by the reality of the working relationship rather than the label on the agreement, so a long-standing consultant who works set hours, uses company equipment, has no right of substitution and takes direction day to day may well be a worker or an employee whatever their contract says.
The exposure is real and cumulative: unpaid holiday pay, pension contributions, employer’s National Insurance, and potentially unfair dismissal rights. A buyer that spots it will ask for a specific indemnity, and specific indemnities are usually uncapped and untimed. Review the arrangements, bring the documentation into line with the reality, and where the reality is employment, deal with it before you market. Our employment team acts for employers and employees on exactly these questions, which means we see how the arguments run from both sides.
Where the sale is structured as an asset sale, or where the business operates through a service contract that is changing hands, the employees transfer automatically under TUPE and the information and consultation obligations bite on both parties. We set out the mechanics in our guide to TUPE when buying or selling a business.
Intellectual property: the assignments nobody signed
Intellectual property ownership is the workstream most likely to produce a defect that cannot be fixed with money, and it rests on two provisions worth knowing.
Under section 11 of the Copyright, Designs and Patents Act 1988 the author of a work is the first owner of copyright in it. The exception, in section 11(2), is that where a literary, dramatic, musical or artistic work, or a film, is made by an employee in the course of their employment, the employer is the first owner, subject to any agreement to the contrary. There is no equivalent for contractors. A freelancer, agency or self-employed developer owns the copyright in what they create unless they have assigned it.
Under section 90(3) of the same Act, an assignment of copyright is not effective unless it is in writing signed by or on behalf of the assignor. An invoice marked “full rights” does not do it. An email saying “it’s all yours” does not do it. A purchase order does not do it.
Put those two together and the common SME position becomes clear. The website, the brand assets, the app, the bespoke software and the technical drawings were frequently created by people who were not employees, under no written assignment. The company has been trading on intellectual property it does not own.
The founder version is worse, and more common than sellers expect. Where the founder built the product personally before the company was incorporated, or alongside employment by a previous business, the copyright may never have reached the company at all. Fixing it means tracing the creators and obtaining signed written assignments, which is easy where the relationship is current and good, and hard where the freelancer has moved on, changed country or fallen out with you. Sixteen weeks is not an unusual lead time.
Alongside copyright, check that trade marks are registered in the company’s name rather than the owner’s, that they are in force and cover the classes and territories actually used, and that domain names and social media accounts are held by the company rather than by an employee or a former web developer. Our intellectual property due diligence work on transactions exists largely because this is the area where diligence most often finds something that genuinely has to be solved rather than priced.
Property: title, leases and landlord’s consent
Where the business owns its premises, obtain official copies of the register and title plan early and check that the registered proprietor is the company, that the plan matches what you actually occupy, and that the rights of access and services the business depends on are included. Title defects, unregistered extensions and missing rights of way take months to resolve and cannot be compressed.
Where the business leases its premises, the lease paperwork is the priority: the lease itself, every licence and deed of variation, the rent deposit deed, rent review memoranda, and the licences for any alterations you have made. Unconsented alterations become a reinstatement liability at the end of the term, and a buyer will deduct for it or require it covered. We set out the clauses that cause the most trouble in our piece on commercial lease red flags.
The item to start earliest is landlord’s consent, because it is the one you control least.
Where a lease contains a covenant against assigning, underletting, charging or parting with possession without consent, section 19(1)(a) of the Landlord and Tenant Act 1927 deems that covenant subject to a proviso that the licence or consent is not to be unreasonably withheld, although the landlord can still require payment of a reasonable sum for the legal and other expenses of dealing with the application. Where the covenant is qualified in that way, section 1(3) of the Landlord and Tenant Act 1988 imposes a duty on the person who may consent, once a written application is served, to give consent within a reasonable time except where it is reasonable not to, and to serve written notice of the decision specifying any conditions or, where consent is withheld, the reasons. If the question arises whether consent was given within a reasonable time, it is for the landlord to show that it was.
Those provisions help, but they do not make the process quick. Six to sixteen weeks is realistic, longer where the landlord wants a rent deposit, a guarantee from the buyer or an authorised guarantee agreement from you. On a share sale, check whether the lease contains a change of control provision, since the tenant entity is not changing and a straightforward alienation covenant may not be engaged at all. Our commercial property team handles consent applications as part of sale preparation for exactly this reason.
Licences and regulatory registrations
List every licence, permit, approval and registration the business needs in order to trade, with the holder, the expiry date and the renewal position. A licence held by the owner personally rather than the company, or one that lapsed quietly two years ago, can stop the business trading on day one under new ownership.
The structure of the deal determines how licences are handled. On a share sale the licence holder is the same legal entity before and after, so licences usually continue, although many regulators require notification of a change of control and some require fresh approval. On an asset sale the buyer is a different entity and generally needs its own licence or registration, which can be the longest item on the entire timetable.
In regulated sectors the regulator sets the pace. The Care Quality Commission treats a change of registered provider as a sale and transfer, requiring applications from both the outgoing and the incoming provider at around the same time, which it links and assesses together. Registration is completed only when the Commission receives formal confirmation from both providers’ legal representatives that the sale and transfer is complete. Registered managers at the location must separately apply to continue their registration under the incoming provider, cancel, or remove the location from their registration.
The practical consequence is that in a regulated business the lawyers are not the constraint. We act on transactions in care homes, pharmacies and dental practices, where the sequencing between the legal documents and the regulatory applications is often the hardest part of the deal to manage. Our pieces on the CQC application process on a practice sale and selling a dental practice work through a sector example in detail.
Data protection records
A buyer will warrant-check data protection compliance, and the evidence it asks for is documentation. Under Article 30 of the UK GDPR, organisations with 250 or more employees must document all their processing activities. Organisations employing fewer than 250 people benefit from a limited exemption and need only document processing that is not occasional, or that is likely to result in a risk to the rights and freedoms of individuals, or that involves special category data or criminal conviction and offence data.
The exemption is narrower than most small businesses assume. The ICO’s own example is an insurance company with 100 staff that must still document the processing it carries out for claims, sales and HR, because that processing is not occasional. Almost any trading business with employees and customers is processing personal data on a routine basis, so in practice most businesses need a record of processing activities.
Assemble the record of processing, privacy notices, data processing agreements with your suppliers, the retention policy, the breach log and any data protection impact assessments. The absence of a record of processing is not just a missing document in the data room: where the obligation applies, it is itself the breach. The ICO has noted that its documentation guidance is under review following changes made by the Data (Use and Access) Act, so check the current position when you prepare the file rather than relying on a template. Our data protection team reviews these records before sale, and our piece on UK cybersecurity and privacy laws covers the wider compliance picture.
Litigation and threatened claims
Prepare a schedule of every live claim, employment tribunal case, debt recovery action, formal complaint and threatened claim, with its current status, the next procedural date and an honest estimate of exposure. Include the matters that have gone quiet but have not been settled or struck out.
A claim disclosed early is a negotiated allocation of risk, usually handled by a specific indemnity or a retention whose size you have had a hand in agreeing. The same claim found by the buyer’s solicitors in week six of diligence is handled on the buyer’s terms, and it damages your credibility on everything else you have told them. If there is something you would rather the buyer did not see, that is precisely the item to deal with first, either by resolving it or by planning how you present it. Our dispute resolution team advises sellers on both.
Sequencing: start with what you cannot speed up
The order of work matters more than the length of the list. Almost everything that takes a long time takes a long time because somebody else has to agree to it, and no amount of urgency changes that.
Sequencing a vendor due diligence exercise: slowest items first
| 1 | Months 6 to 12 before marketingStart the slow items Register of members reconstruction, IP assignments from former freelancers and founders, trade mark and domain transfers, title defects, landlord consent where the lease requires it, and anything needing a regulator’s involvement. None of these can be compressed by spending more money, so they go first. |
| 2 | Months 4 to 6 before marketingContracts and people Chase signatures on material contracts, renew expired terms, issue written statements of particulars, document undocumented employment variations, and resolve contractor status questions. This is the largest volume of work and the most administrative. |
| 3 | Months 2 to 4 before marketingCompanies House and corporate records Bring filings up to date, complete identity verification for directors and PSCs, correct the PSC entries, release satisfied charges, and assemble signed minutes for every corporate action. |
| 4 | Months 1 to 2 before marketingBuild the data room Index everything by workstream, in the order a buyer’s solicitor will ask for it. The index is what a buyer judges you on in the first week, and it becomes the backbone of your disclosure bundle later. |
| 5 | Final weeks before marketingRun the buyer’s questionnaire against yourself Work through a real legal due diligence questionnaire and answer it honestly in writing. Whatever you cannot answer is what the buyer will find. Fix it, or decide now how you will present it. |
Six to twelve months before marketing is the ideal starting point for a business of any complexity. Three months is enough to make a real difference. Even four weeks spent reconstructing the register of members and chasing the signatures on your five largest contracts will change what a buyer finds.
How vendor due diligence feeds the disclosure letter
There is a direct connection between this exercise and the document that will eventually protect you from a warranty claim. The disclosure letter is where the seller qualifies the warranties by telling the buyer what is actually true, and a disclosure only works if it is full and fair.
A seller who has already worked through their own position warranty by warranty knows what needs disclosing, has the documents to support it, and can draft specific disclosures with enough detail to be effective. A seller who has not will be drafting the disclosure letter in the final fortnight, from a data room they have not read, against warranties they have not analysed. That is how general disclosures that protect nobody get written.
The same applies to price protection mechanisms. Where part of the consideration is deferred or structured as an earn-out, the buyer’s view of risk shapes the structure. Clean records narrow what the buyer needs to hold back.
Common questions
Do I need to pay for a formal vendor due diligence report?
Usually not, if you are selling an owner-managed business to a single buyer. A formal report earns its fee where several bidders are competing, where management time is the binding constraint, or where a financial seller needs a controlled auction. For most SME sales the money is better spent on the legal preparation itself, because that is what removes price risk.
When should I start?
Six to twelve months before you want to go to market, if you can. The items that drive the timetable are the ones needing a third party’s agreement: freelancer IP assignments, landlord’s consent, customer signatures, regulatory applications. Those are the ones to start first, and they do not get faster with urgency.
Will my buyer still do its own due diligence?
Yes. Vendor due diligence does not replace the buyer’s investigation and no competent buyer would let it. What it does is shorten that investigation, reduce the number of findings, and change the character of the ones that remain from discoveries into things you have already explained.
Should I tell my staff or my customers?
Not while you are preparing. Almost all of this work can be presented internally as a records and compliance tidy-up, which is what it is. Chasing a signature on an expired contract is normal commercial housekeeping and does not need a reason attached. Confidentiality before and during a sale process is a commercial priority in its own right.
What if I find something I cannot fix?
Some things cannot be put right in the time available: a founder who will not sign an IP assignment, a title defect requiring an indemnity policy, a claim that will not settle. Knowing about it in advance is still worth a great deal, because you can decide how to present it, obtain a valuation of the exposure, price it into your expectations, and choose the deal structure that handles it best. The worst outcome is not an unfixable problem. It is an unfixable problem you learn about from the buyer.
The practical takeaway
Vendor due diligence on an SME sale is not a report you buy. It is the discipline of running a buyer’s questionnaire against your own business early enough that the answers can still be changed. The defects it finds are mundane, and that is the point: a register of members nobody updated, a certificate nobody can find, a contract nobody signed, an assignment nobody took. Each one is cheap to fix in advance and expensive to fix under negotiation.
Start with the items a third party controls, because those set your timetable. Keep the corporate records in order as a matter of routine rather than as a pre-sale project, and use the next twelve months to get identity verification, filings and the members’ register into a state you would be happy for a buyer’s solicitor to read. The reward is not a tidier folder. It is a sale that completes on your terms, at the price you agreed.
We act for both sellers and buyers on share and asset sales of owner-managed businesses, including regulated businesses where the regulator’s timetable governs the deal. If you are planning an exit, we run vendor due diligence exercises as a discrete piece of work before marketing, and you can read more about our approach to selling a business and buying a business, as well as our wider mergers and acquisitions and management buy-out and buy-in practice.
If you are thinking about selling in the next year or two and want to know what a buyer would find, we are happy to talk it through and give you an honest view of what needs doing first. Call us on +44 207 566 1188 or email info@gurvelegal.com.
This article sets out the general legal position as at 6 October 2026 and is not advice on any particular transaction. Tax points are included for context only: confirm your own stamp duty and capital gains position with your accountant or tax adviser.


