Value Added Tax (VAT) risks in business acquisitions rarely appear as one obvious error. More often, they’re spread across customer contracts, property decisions, overseas registrations, supplier invoices and group accounting. Individually, each point may look manageable; together, they can alter the value and risk profile of a transaction.
For a buyer, an unidentified liability may lead to additional costs after completion or show that forecast margins are unreliable. For a seller, a late VAT discovery can trigger a price adjustment, a specific indemnity, wider warranties or delays while the parties work out the exposure.
Effective VAT due diligence therefore needs to test how the business makes VAT decisions, not simply whether figures were entered on a return. The review should follow the commercial activity from the first customer or supplier record through to invoicing, accounting, reporting and evidence.
Do not start with the VAT return
A return is the final output of many earlier decisions. It won’t, on its own, explain whether the correct VAT treatment was selected, whether a foreign registration was missed or whether purchase VAT was claimed by the right company.
A transaction-focused review starts by mapping the business: its revenue streams, customer types, operating territories, property interests, major costs and legal entities. Sample transactions can then be traced through contracts, invoices, accounting entries and VAT returns.
This is particularly important for consumer-facing organisations and businesses in financial services, insurance, health and education, where restricted recovery can turn VAT into a direct operating cost. The HMRC VAT guide (VAT Notice 700) provides the wider framework for VAT registration, accounting and payment.
Trace the VAT through revenue
The starting point is to understand what the business actually supplies. VAT exemptions are subject to detailed conditions and should be tested against the contracts and the service delivered in practice. If taxable income has been treated as exempt, VAT may have to be accounted for from the price already charged to the customer.
A useful revenue map separates the main categories rather than grouping all sales on which UK VAT was not charged. These categories may include:
- UK supplies charged at the standard, reduced or zero rate
- Exempt supplies that may restrict input VAT recovery
- Amounts that fall outside the scope of UK VAT
- Cross-border supplies whose treatment depends on the customer, location and nature of the supply
- Internal transactions that may be disregarded within a UK VAT group
An invoice without UK VAT isn’t evidence of an error by itself. The business must be able to explain the legal basis for the treatment and retain the proof it requires. Exported goods, for example, qualify for zero rating only when the relevant conditions are satisfied and the necessary export evidence is held within the permitted timeframe.
Test international obligations in the countries that matter
A UK establishment doesn’t confine a business’s VAT obligations to the UK. Cross-border sales can create registrations and recurring filings elsewhere, depending on the country, the supply, the customer’s VAT status and any threshold or simplification available.
The place-of-supply rules help determine which country has the right to tax a service. The rules can change according to the nature of the service and whether the customer is a business or consumer. Further detail is available in HMRC’s place of supply of services guidance (VAT Notice 741A).
Historic registration dates can extend back over several years. Where the customer is a consumer, it may no longer be commercially possible to collect the additional VAT, leaving the business to fund the tax, interest and any penalties itself.
VAT due diligence for acquisitions should therefore compare where customers and supplies are located with the registrations and filings shown in the data room.
Put property on its own workstream
Property can generate a material VAT exposure even when real estate isn’t the target’s main business. The analysis turns on several connected facts: the asset’s nature and age; any option-to-tax election; its current and intended use; each party’s position; and whether the transaction meets the conditions for a transfer of a going concern.
Because the underlying values are often significant, a single incorrect assumption can create a large liability or cash-flow requirement. Options to tax, supporting correspondence, lease terms and previous transactions should be reviewed as a connected evidence set rather than as isolated documents.
Follow the purchase invoices
VAT registration doesn’t make every purchase claim valid. Input VAT is generally recoverable only to the extent that the cost supports taxable or other qualifying activities. The usual conditions covering business use, attribution, blocked input tax and supporting evidence still apply.
Due diligence often reveals invoices addressed to the wrong group company, missing tax invoices, inconsistent coding or costs claimed without a clear link to the claimant’s activities. Those findings affect more than the value of the historic claim: they can indicate whether the wider VAT control environment is dependable.
Look for reverse charge costs that never appear on a supplier invoice
For certain services bought from a non-UK supplier, the UK customer may need to account for VAT under the reverse charge. A business that isn’t yet registered must also include relevant business-to-business (B2B) general-rule services when it tests whether the UK registration threshold has been crossed.
The reverse charge may be broadly neutral for a fully taxable business, but it can become a real cost where input VAT recovery is restricted. Software licences, cloud services, professional advice, online advertising and overseas group charges are common areas to test.
The contractual supplier and the establishment providing the service matter more than the brand name on the purchase order. VAT Notice 741A explains the place-of-supply and reverse-charge rules for services.
Challenge partial exemption before the buyer does
A partly exempt business must first attribute purchase VAT directly to activities that carry or don’t carry a right to deduct. Residual VAT then needs to be apportioned under the applicable method, with an annual adjustment where required.
Calculations can be missed or cease to reflect the business after an acquisition, restructuring, change in activity or change to a VAT group. A buyer will want to understand both the numerical exposure and whether the method still produces a fair and reasonable result for the way costs are actually used.
HMRC sets out the relevant calculations, methods and adjustments in its partial exemption guidance (VAT Notice 706).
Intercompany accounting can hide real supplies
Management charges, shared costs and other entries between separate legal entities can represent supplies for VAT purposes where the companies aren’t members of the same UK VAT group. Posting an amount only through intercompany accounts, or not raising a conventional invoice, doesn’t remove the need to consider VAT.
Connected-party rules also need attention. Where the prescribed conditions are met, HM Revenue & Customs (HMRC) can require open-market valuation, particularly when the customer has restricted recovery. The legislative basis for these valuation rules can be found in Schedule 6 of the Value Added Tax Act 1994.
HMRC may separately challenge a claim made by one entity for expenditure that, in substance, supports another. Agreements, allocation methods, VAT-group membership and the commercial purpose of each charge should all tell the same story.
Quantify historic exposure before deciding how to correct it
Businesses will usually need to look back four years when correcting VAT errors. HMRC can assess earlier periods in some circumstances, with a longer reach where behaviour was deliberate. Underdeclared tax can generate late-payment interest, while the penalty position will depend on what happened and the standard of care taken.
The supplier may owe interest even if its customer could have deducted the underlying VAT. Where the customer is unregistered or has limited recovery, the tax itself may also become an irrecoverable commercial cost.
The correct sequence is to confirm what occurred, calculate the affected amounts and periods, assemble the evidence and only then select the appropriate correction or disclosure route. VAT Notice 700/45 explains how VAT errors should be corrected and when they need to be separately notified to HMRC.
Build an evidence pack, not just an explanation
A technically reasonable answer can still be difficult to defend if the records are incomplete. Buyers commonly ask for the same evidence that HMRC would expect during an enquiry, including:
- Valid purchase invoices
- Contracts
- Customer-location evidence
- Proof of export
- Option-to-tax records
- Property analyses
- Partial exemption calculations
- Support for intercompany charges
Businesses must keep suitable VAT records and retain them for the required period. The detailed requirements are covered by HMRC’s record-keeping guidance (VAT Notice 700/21).
Sellers are usually in a stronger position when the analysis is completed before the data room opens. It allows them to explain an issue accurately, show how it has been quantified and demonstrate what corrective action is already under way.
A practical VAT due diligence checklist
For a focused pre-deal review, the transaction team should be able to answer:
- Do the main revenue streams have the correct VAT liability and supporting rationale?
- Do overseas customer and supply locations reconcile with VAT registrations and filings?
- Have property transactions, options to tax and transfer-of-business conditions been checked?
- Can purchase VAT claims be tied to the correct company, activity and evidence?
- Have overseas services and group allocations been tested for reverse charge VAT?
- Are partial exemption calculations, annual adjustments and methods complete and current?
- Do intercompany agreements, accounting entries and VAT-group treatment agree?
- Have historic errors been quantified and the correct correction or disclosure route identified?
- Is the supporting VAT evidence organised and ready for buyer or HMRC scrutiny?
The aim isn’t to produce the longest possible issues list. It’s to identify the VAT matters that can affect deal value, cash flow, contractual protection or the buyer’s post-completion plan, and to address them while there’s still time to act.
How The VAT Consultancy can help
The VAT Consultancy can provide buy-side or vendor reviews through our VAT Risk Management and Control team. We can test the issues most likely to affect a transaction, quantify historic exposure and help the business improve its processes and evidence.
Where a review identifies cross-border or property questions, our Ad hoc UK and Global Advisory and Land and Property specialists can support the detailed analysis. We can also help with corrections, disclosures to HMRC and the practical steps needed before or after completion.
Bringing VAT specialists into a purchase, sale or refinancing at an early stage gives the transaction team better visibility of the exposure and a wider choice of practical responses.
If you are interested in working with the VAT Connsultancy – Contact us today.
