VAT Investigations: The Complete UK Guide

VAT is the tax HMRC investigates most aggressively. With Making Tax Digital feeding live data into HMRC’s risk engine and joint and several liability rules pulling unconnected businesses into fraud chains, even a clean return can attract a check. This guide explains every type of VAT enquiry, how HMRC selects businesses, the officer’s legal powers and how to defend yourself at each stage.

Types of VAT enquiry

HMRC has several escalating procedures for examining a business’s VAT affairs. The label on the letter matters: it dictates the officer’s powers, your obligations and the realistic worst-case outcome.

1. Routine compliance check

The lightest form of enquiry. Often triggered by a single anomaly, an unusual repayment claim, a sudden change in turnover or a sector-risk indicator. The opening letter normally asks for specific records covering one or two return periods and is signed by a Compliance Officer in HMRC’s Wealthy & Mid-Sized Business or Individual & Small Business Compliance directorate.

2. Full VAT enquiry

A broader review of multiple periods, often accompanied by a request for a meeting at the trading premises. Officers will examine source records (sales day books, purchase invoices, till rolls, e-commerce platform reports) and reconcile to the VAT account.

3. Civil investigation under COP8

Run by HMRC’s Fraud Investigation Service (FIS) where the issues are technically complex or the amounts large but fraud is not alleged. Common in marketed avoidance, partial exemption disputes and large group reorganisations.

4. Civil investigation of fraud under COP9

The most serious civil procedure. HMRC suspects deliberate VAT fraud and offers the Contractual Disclosure Facility (CDF) in exchange for immunity from prosecution. See our full COP9 guide for the procedural detail.

5. Criminal investigation

Reserved for the most serious cases, MTIC and carousel fraud, organised evasion, abuse of HMRC officials or refusal to engage with COP9. Conducted by HMRC’s Criminal Investigators under PACE rather than tax legislation.

How HMRC selects businesses for VAT review

VAT selection used to be dominated by random sampling. It isn’t any more. The current model is overwhelmingly data-led.

• Making Tax Digital (MTD) data. Since MTD became mandatory, HMRC ingests the digital VAT account itself. Box-to-box trends across periods are compared against sector norms in real time.
• Voluntary disclosure mismatches. Where a disclosure under VAT Notice 700/45 cannot be reconciled to the return history, the file is automatically flagged.
• Behavioural sector-risk indicators. Cash-heavy trades, takeaways, taxi firms, builders, scrap metal, mobile phones and online resellers carry elevated risk weights.
• Third-party data. Card-acquirer reports (under Sch 23 FA 2011), online marketplace reports, gig-economy platform data and Companies House filings are all imported and cross-matched to declared turnover.
• Connect, HMRC’s anti-fraud risk engine. Cross-references over 30 billion data points across UK and overseas sources to score every trader.
• Supply chain pattern detection. Particularly for goods that historically feature in MTIC fraud (chips, phones, alcohol, carbon credits, telecoms minutes), HMRC traces transaction chains looking for missing-trader indicators.
• Open-source intelligence. Trustpilot reviews, LinkedIn, social media and even Google reviews showing turnover inconsistent with returns.

Typical technical pressure points

Most VAT enquiries we see do not involve fraud. They involve genuine technical errors at a handful of recurring pressure points:

• Option to tax (OTT) errors. Missing notifications, OTT exercised by the wrong group entity or supplies treated as opted when the property was never validly opted.
• Partial exemption. Method failures, standard method override (SMO) calculations missed or annual adjustments forgotten.
• Place of supply. Particularly in services to overseas customers post-Brexit, the use-and-enjoyment rules and the B2B vs B2C distinction generate routine errors.
• Zero/reduced rating misapplied. Food (the Jaffa Cake problem), construction (zero-rating only for new build dwellings), printed matter and energy-saving materials.
• B2C vs B2B classification. Affects place of supply, MOSS/OSS scope and invoicing.
• Retail schemes. Apportionment Scheme 1/2 and Direct Calculation Scheme 1/2 calculations breaking down at scale.
• Margin scheme misuse. Second-hand goods, antiques and cars, particularly where stock books are incomplete.
• Intra-group transactions. Recharges, management services and dilapidation provisions across VAT groups.

The enquiry process step by step

1. Opening letter. Schedule 36 information notice or informal records request. Read it carefully, the framing tells you a lot about how the officer sees the case.
2. Initial response. Identify the issue, scope the risk, decide who replies. Do not volunteer information not requested.
3. Records production. Producing a properly organised, indexed bundle reduces the number of follow-up questions dramatically.
4. Officer review. The officer works through the records, often building a schedule of suggested adjustments.
5. Meeting (optional). Many VAT enquiries are resolved by correspondence. Where meetings happen, your adviser should attend and take a contemporaneous note.
6. Officer’s position letter. A schedule of proposed assessments and penalty stance.
7. Response and negotiation. Technical and factual challenge before figures are crystallised.
8. Closure notice and assessment. Formal statutory document opening the 30-day appeal window.

HMRC’s information powers (Schedule 36 FA 2008)

Schedule 36 to Finance Act 2008 is the single most important piece of legislation in any VAT enquiry. It gives HMRC the right to require “information and documents” that are “reasonably required” to check a tax position.

Formal information notices (Sch 36 para 1)

A taxpayer notice issued under paragraph 1 is legally binding. Failure to comply attracts an initial £300 penalty and £60 per day continuation penalties. The notice can be appealed only on limited grounds (mainly that the information is not “reasonably required”).

Third-party notices (Sch 36 para 2)

HMRC can require a third party, a bank, supplier, customer, accountant or marketplace, to provide information about you. The taxpayer is usually (but not always) told. Where the notice is approved by the First-tier Tribunal, the taxpayer can be excluded entirely.

Premises inspections (Sch 36 para 10)

HMRC officers can enter business premises and inspect business assets and records. Inspections of premises also used as a dwelling require the occupier’s consent or tribunal approval.

Officer powers vs criminal powers

Once HMRC believes the case may proceed criminally, the legal framework shifts entirely. Schedule 36 stops applying. Investigators operate under the Police and Criminal Evidence Act 1984 (PACE), the same legislation that governs the police.

Differences include:

• Interviews are conducted under caution with the right to silence and to legal representation
• Search warrants must be granted by a magistrate (s8 PACE)
• Compelled disclosure under Sch 36 cannot be used in a subsequent criminal prosecution
• The standard of proof is “beyond reasonable doubt” rather than the civil “balance of probabilities”

The transition point, civil to criminal, is rarely visible to the taxpayer. By the time you find out, the file has often been with HMRC’s Criminal Investigators for months.

Responding to a VAT compliance check letter

The first response is the most important document in the file. Common mistakes:

• Treating the letter as a routine query and replying without scoping the underlying risk
• Volunteering information that wasn’t asked for
• Sending raw records without any narrative or index
• Agreeing to a meeting on HMRC’s preferred timetable before understanding the issues
• Allowing the bookkeeper or in-house finance team to deal with HMRC directly

The disciplined approach: pause, read carefully, identify the underlying technical issue, brief a specialist and respond strategically.

Closure notice & assessment

VAT assessments are issued under section 73 VATA 1994 (best judgment) or section 77 (prescribed accounting period). The assessment is the formal demand for tax, separate from any penalty assessment which follows under Schedule 24 FA 2007. See our companion guide on VAT penalties and the dedicated VAT assessment appeal page.

Appeals: HMRC review and First-tier Tribunal

You have 30 days from the date of the assessment to either:

1. Request an HMRC internal review under section 83A VATA 1994, or
2. Appeal directly to the First-tier Tribunal (Tax Chamber)

Internal reviews succeed in roughly 30% of cases by changing the assessment in some way. Where the review confirms the assessment, a further 30 days runs from the review conclusion letter for an appeal to the FtT. Full procedural detail is on our VAT assessment appeal page.

Time limits (4/6/20 years)

Assessment time limits are at section 77 VATA 1994:

• 4 years , standard limit from the end of the prescribed accounting period
• 6 years , where the loss of VAT is brought about by careless behaviour
• 20 years , where the loss is deliberate or where the trader failed to register

Within these windows, HMRC must still raise the assessment within 1 year of having sufficient evidence to do so. Late assessments can be challenged on the “evidence of facts” ground at section 73(6).

How we help

Tax Dispute Consultants is a specialist tax investigation practice. For VAT investigations we:

• Take over all HMRC correspondence and meetings
• Scope the underlying technical issue before responding to the opening letter
• Challenge improper Schedule 36 notices and third-party notices
• Negotiate the assessment figures, penalty behaviour categorisation and quality-of-disclosure reductions
• Run internal reviews and First-tier Tribunal appeals

Frequently asked questions

Related guides

• MTIC / carousel fraud explained
• How to appeal a VAT assessment
• VAT penalties: how HMRC calculates them
• COP9, the complete guide
• HMRC penalty calculator