HMRC Compliance Check 2026: What to Do if You Receive an Enquiry Letter

Types of HMRC enquiries

HMRC conducts two main types of enquiries into tax returns: aspect enquiries (limited scope) and full enquiries (comprehensive).

Aspect enquiry (limited scope)

An aspect enquiry focuses on one specific item or area of your tax return. HMRC suspects an issue with a particular income source, deduction, or claim.

Examples:

• You claim GBP 8,000 in home office costs; HMRC questions if this is reasonable
• You declare GBP 45,000 self-employment income; HMRC asks for supporting invoices and bank statements
• You claim GBP 12,000 in charitable donations; HMRC requests donation receipts
• You claim capital gains loss of GBP 25,000; HMRC asks for transaction documentation

Characteristics:

• ✓ Narrow in scope (one item or category)
• ✓ Faster to resolve (typically 3-6 months)
• ✓ Lower risk (limited exposure to penalties)
• ✓ Most common type of enquiry

Full enquiry (comprehensive)

A full enquiry investigates all aspects of your tax return and possibly multiple years.

Examples:

• Your business income has grown 300% year-on-year; HMRC audits all records and transactions
• Self-employed income declared GBP 50,000 but bank statements suggest GBP 150,000; HMRC conducts full enquiry
• Multiple years of returns show inconsistent patterns; HMRC investigates several years
• Offshore income or complex structures; HMRC conducts full enquiry

Characteristics:

• ✗ Broad in scope (all income, deductions, reliefs)
• ✗ Longer to resolve (6 months to 2+ years)
• ✗ Higher risk (larger exposure to adjustments and penalties)
• ✗ More common if pattern of concern identified

Timescales and deadlines

When can HMRC issue an enquiry notice?

HMRC must issue a notice of enquiry within:

• 12 months of filing the return (standard rule for Self Assessment)
• 4 years if HMRC suspects deliberate understatement (fraud investigation)
• 20 years in cases of fraud prosecution

Example: If you file your 2025/26 return on 31 January 2027, HMRC can issue an enquiry notice up to 31 January 2028 (12 months).

The enquiry process timeline

Once HMRC issues a notice:

1. Enquiry notice issued: HMRC sends formal letter opening enquiry
2. Information request (within 30 days): HMRC requests specific records
3. Your response (within 30 days): You provide documents and explanations
4. HMRC review (2-8 weeks): Officer reviews your submission
5. Preliminary findings (if required): HMRC outlines issues identified
6. Negotiation/settlement (2-12 weeks): Discussion of adjustments and penalties
7. Closure notice: HMRC issues formal closure notice (agreement or assessment)

Total typical timeframe: 3-6 months (aspect enquiry) to 1-2 years (full enquiry).

What records HMRC can request

HMRC has broad powers to request records relevant to your tax liability.

Standard record requests (6-year retention)

• ✓ Bank statements and building society statements
• ✓ Invoices (both issued and received)
• ✓ Receipts and expense documentation
• ✓ Business accounts and contracts
• ✓ Payroll records and P60s
• ✓ VAT returns and VAT documentation
• ✓ Pension contribution statements
• ✓ Property rental records and tenancy agreements
• ✓ Investment statements and brokerage confirmations
• ✓ Trust or partnership documents

Extended record requests (20-year retention if suspected deliberate)

If HMRC suspects deliberate fraud or understatement, they can request records back 20 years (rather than the standard 6 years).

Timescale for providing records

• Standard: 30 days from HMRC request
• Extended: Can negotiate extension (typically another 30 days)
• Failure to provide: Constitutes a separate offence (penalties up to GBP 3,000)

If you genuinely cannot find records (e.g., bank statements from 6 years ago), explain to HMRC and provide what you can, along with explanations of unavailable documents.

HMRC Charter: Your rights during an enquiry

The HMRC Charter outlines your rights during an enquiry. HMRC officers must:

✓ Treat you professionally and fairly -- no harassment, unreasonable demands

✓ Explain decisions -- provide clear reasons for adjustments or penalties

✓ Respect your privacy -- only request information relevant to the enquiry

✓ Allow reasonable time -- typically 30 days to respond to information requests

✓ Consider your circumstances -- health issues, language barriers, disability accommodations

✓ Keep things proportionate -- request scope matched to enquiry significance

If you feel HMRC has breached the Charter, you can complain to the Adjudicator (independent complaints body).

Penalties: Behaviour-based structure

HMRC penalties for errors depend on the behaviour leading to the error, not the error amount.

Careless penalty (30-100% of tax owed)

Careless means you failed to take reasonable care in preparing your return. You made an honest mistake but should have known better.

Examples:

• Claimed GBP 12,000 home office deduction without calculating actual costs (reasonable care would involve working backwards from bills)
• Forgot to include bank interest on one account (reasonable care = reviewing all statements)
• Misclassified expense (e.g., claimed personal clothing as uniform)
• Estimated income without supporting records (should have calculated precisely)

Penalty calculation:

• Minimum: 30% of unpaid tax (if HMRC finds error first)
• Maximum: 100% of unpaid tax (if behaviour particularly sloppy)
• Reduction: If you disclose error before HMRC finds it, penalty reduced by 50% (15-50%)

Example:

• Additional tax found: GBP 5,000
• Penalty (if careless, not disclosed): GBP 1,500-5,000 (30-100%)
• If you disclosed it yourself: GBP 750-2,500 (15-50% after disclosure reduction)

Deliberate penalty (70-200% of tax owed)

Deliberate means intentional understatement. You knew the return was wrong but submitted it anyway (or deliberately withheld information).

Examples:

• Failed to declare GBP 50,000 self-employment income you knew about
• Deliberately inflated deductions (e.g., claimed GBP 15,000 home office knowing actual is GBP 3,000)
• Undeclared offshore income or accounts
• Submitted invoice to inflate business income (knew it was false)

Penalty calculation:

• Minimum: 70% of unpaid tax (if you cooperate with HMRC and come clean)
• Maximum: 200% of unpaid tax (if you conceal evidence or resist investigation)
• Reduction: If you disclose and cooperate, penalty reduced by 50% (35-100%)

Example:

• Unpaid tax: GBP 30,000
• Penalty (deliberate, discovered by HMRC): GBP 21,000-60,000 (70-200%)
• If you disclosed it yourself early: GBP 10,500-30,000 (35-100% after reduction)

Other behaviour categories

Negligent (not following professional advice):

• Penalty: 50% of tax owed
• Example: Accountant advised GBP 5,000 allowance; you claimed GBP 15,000 anyway

Reckless (behaviour very unreasonable):

• Penalty: 70% of tax owed
• Example: No records kept, rough guesses on all figures

Settlement and dispute resolution

HMRC's closing statement

Once HMRC completes its review, it issues a Closure Notice or Assessment detailing:

• Items accepted (no adjustment)
• Items adjusted (additional tax/loss)
• Penalty (if applicable)
• Interest on unpaid tax (at HMRC rate, currently 8% per annum)

You then have 30 days to:

1. Accept the assessment (pay any tax owed)
2. Negotiate with the HMRC officer (if you disagree with some items)
3. Appeal (if you fundamentally disagree)

Negotiation with HMRC

If you disagree with some adjustments, you can negotiate with the case officer.

Common negotiation scenarios:

• Item 1: HMRC says GBP 12,000 home office unjustified; you offer GBP 5,000 (compromise at GBP 7,000-8,000)
• Item 2: HMRC disallows GBP 3,000 entertainment expenses; you provide evidence that GBP 2,000 is legitimate (compromise at GBP 1,000-1,500)
• Penalty: HMRC calculates careless at 70%; you negotiate to 50% based on full cooperation

Negotiations often result in split-the-difference settlements where both sides give ground.

Appeal to tax tribunal

If negotiation fails, you can appeal to the First-tier Tribunal (Tax Chamber) within 30 days of the closure notice.

Tribunal appeal process:

1. Notice of appeal submitted to HMRC (must state grounds within 30 days)
2. HMRC response (exchange of evidence and documents)
3. Tribunal hearing (judge listens to both sides, decides)
4. Tribunal decision (binding unless appealed to Upper Tribunal)

Appeals are decided by judges based on evidence, not on compromise. You either win or lose (no split-the-difference). Many advisers recommend settlement negotiations before appealing because tribunal outcomes are binary.

Getting professional help

When to engage a tax adviser

You should consider professional help if:

✓ The enquiry involves complex issues (partnerships, trusts, overseas income)

✓ Penalty risk is material (GBP 5,000+)

✓ You are uncomfortable dealing with HMRC directly

✓ The enquiry is full scope (all aspects of return)

✓ You lack detailed records (adviser can help reconstruct)

Types of professionals

Tax Accountant (ACCA, CIOT, etc.):

• Hourly rate: GBP 150-300/hour
• Cost for aspect enquiry: GBP 1,500-3,000
• Cost for full enquiry: GBP 5,000-15,000
• Benefits: Handles all correspondence, negotiates with HMRC, provides representation at meetings

Tax Specialist/Adviser:

• Hourly rate: GBP 100-200/hour (often cheaper than accountants)
• Similar cost structure to accountants
• Benefits: Specialized in enquiry resolution, often experienced negotiators

In-house support (if employed):

• Some employers provide tax dispute support through benefits package
• Free to employee but employer may recoup costs if enquiry relates to employment

Cost recovery

If you are assessed to pay additional tax due to careless (but not deliberate) error, professional fees are often recoverable as a deduction against income. You can claim adviser fees as a professional business expense, reducing taxable income.

Example:

• Additional tax assessed: GBP 5,000
• Professional fees: GBP 2,000
• You can claim GBP 2,000 against income (reduces future tax liability by GBP 400-800 depending on rate)
• Net cost: GBP 1,200-1,600

This partially offsets the adviser cost.

Practical steps: What to do if you receive an enquiry notice

Step 1: Don't panic (1 day)

Receiving an enquiry letter is not a crisis. HMRC issues thousands annually, most resolve without penalty.

Step 2: Read the notice carefully (1-2 days)

• Identify the scope (aspect or full enquiry)
• Note specific areas under enquiry
• Note the 30-day deadline for responding

Step 3: Gather records (1-2 weeks)

• Bank statements
• Invoices and receipts (both issued and received)
• Business accounts
• Contracts and agreements
• Payroll records
• Supporting documentation for claimed deductions

Step 4: Assess your position (1 week)

• Are all figures in the return supported by records?
• Were deductions calculated with reasonable care?
• Were any items omitted or misrepresented?
• Do you need professional help?

Step 5: Consider professional advice (1 week)

• If penalty risk or complexity is material, engage accountant or adviser
• Cost typically GBP 1,500-3,000 for aspect enquiry
• Adviser can handle correspondence and negotiate with HMRC

Step 6: Respond to HMRC (within 30 days)

• Provide all requested documents
• Include explanatory letter addressing each enquiry point
• If records are missing, explain why
• If you have identified errors, consider voluntary disclosure (reduces penalty by 50%)

Step 7: Negotiate settlement (1-3 months)

• HMRC may request clarification on some items
• Negotiate adjustments and penalties
• Aim for reasonable compromise

Step 8: Receive closure notice (final)

• Accept assessment or appeal to tribunal within 30 days
• Pay any additional tax owed (plus interest)

Voluntary disclosure: Self-reporting errors

If you discover an error in a previously filed return before HMRC contacts you, voluntary disclosure can significantly reduce penalties.

Disclosure process:

1. Contact HMRC (in writing or via your adviser)
2. Explain the error and why you missed it
3. Provide correct figures and supporting documentation
4. Offer to pay the additional tax owed

Penalty reduction:

• Careless without disclosure: 30-100% of tax
• Careless with disclosure: 15-50% of tax (50% reduction)
• Deliberate without disclosure: 70-200% of tax
• Deliberate with disclosure: 35-100% of tax (50% reduction)

Example:

• Missed GBP 15,000 self-employment income (now realised)
• Additional tax: GBP 3,000
• Without disclosure: Penalty GBP 900-3,000 (careless, 30-100%)
• With disclosure: Penalty GBP 450-1,500 (careless, 15-50% after reduction)

Voluntary disclosure is highly recommended if you identify issues before HMRC does.

Summary and key takeaways

Receiving an HMRC compliance check is not a disaster -- most resolve without material adjustment. Key steps are:

1. Don't panic -- respond professionally and on time
2. Gather records -- evidence is your best defence
3. Consider professional help -- GBP 1,500-3,000 often worthwhile for penalty risk
4. Be honest -- voluntary disclosure reduces penalties significantly
5. Negotiate reasonably -- most cases settle via compromise
6. Know your rights -- HMRC Charter, tribunal appeal available

If you received a compliance check letter, contact a tax adviser immediately to assess your exposure and develop a response strategy.

Use the

to review your tax position and identify any potential issues proactively.