Corporation Tax Record Keeping Requirements

Corporation Tax Record Keeping Requirements: The Complete Guide

Every UK limited company is legally required to keep adequate records for corporation tax purposes. Get it wrong, and you face penalties of up to £3,000 per accounting period, plus the very real risk that HMRC will estimate your tax bill — usually in their favour.

This guide covers everything: what records you must keep, how long to retain them, the shift to digital record keeping, HMRC's inspection powers, and practical tips for staying compliant without drowning in paperwork.

The Legal Requirement

Under Section 12B of the Taxes Management Act 1970 and Paragraph 21 of Schedule 18 to the Finance Act 1998, every company that's required to deliver a corporation tax return must:

1. Keep sufficient records to enable it to deliver a correct and complete return
2. Preserve those records for the statutory retention period

This isn't optional or aspirational — it's a legal obligation with penalties for non-compliance.

What "Sufficient Records" Means

HMRC defines sufficient records as those that:

• Support every figure on the CT600 return and the corporation tax computation
• Allow HMRC to check the accuracy of the return
• Include original documents (or acceptable copies) — not just summaries

In practice, this means you need to be able to trace any number on your CT600 back to source documentation.

What Records Must You Keep?

The records fall into several categories. Here's a comprehensive list:

1. Income and Revenue Records

• Sales invoices — every invoice your company issues
• Credit notes — all credit notes issued
• Till receipts/daily takings records — if you have cash sales
• Contracts and agreements — for major transactions, ongoing contracts
• Bank statements — all business bank accounts
• Building society statements — all business savings accounts
• Records of other income — interest received, rental income, royalties, dividends from investments, foreign income

2. Expenditure Records

• Purchase invoices — from every supplier
• Receipts — for all business expenses
• Petty cash records — with supporting receipts
• Credit card statements — business credit/charge cards with underlying receipts
• Mileage logs — if claiming business mileage
• Travel and subsistence records — with receipts and business purpose noted
• Payroll records — salaries, wages, PAYE, NIC records, P11Ds, P60s
• Pension contribution records — employer and employee contributions
• Rent and lease agreements — for business premises and equipment
• Utility bills — if claiming business premises costs
• Insurance policies and premium records
• Professional fee invoices — accountant, solicitor, other professional services

3. Asset Records

• Purchase and sale documentation for all fixed assets (plant, machinery, vehicles, property, equipment)
• Capital allowances calculations — including pools, additions, disposals, and claims
• Depreciation schedules — even though depreciation itself isn't tax-deductible, HMRC needs to see how you've treated assets in the accounts
• Lease agreements — for hired or leased assets
• Intangible asset records — intellectual property, goodwill, software licences

4. Stock and Work in Progress

• Year-end stock valuations — with details of how values were determined
• Stock count sheets — physical count records
• Write-off records — for obsolete or damaged stock
• Work in progress calculations — with supporting details

5. Director and Shareholder Records

• Director's loan account records — all transactions, balances, interest calculations (see our DLA tax implications guide)
• Dividend records — board minutes declaring dividends, dividend vouchers, payment records
• Share records — register of members, share transfers, allotments
• Benefits in kind records — P11D workings, company car logs, medical insurance

6. VAT Records (If VAT Registered)

• VAT invoices — received and issued
• VAT account — showing output and input VAT
• VAT return working papers
• Import and export documentation

7. Statutory Records

• Annual accounts — profit and loss, balance sheet, notes
• Board minutes — especially those approving financial decisions
• Companies House filings — confirmation statements, accounts filed
• Registered office records
• Corporation tax computations — the workings behind your CT600

How Long Must You Keep Records?

The statutory retention period for corporation tax records is 6 years from the end of the accounting period to which they relate.

The Basic Rule

If your company's accounting period ended on 31 March 2026, you must keep all records relating to that period until at least 31 March 2032.

Extended Periods

In certain situations, records must be kept for longer:

Practical Recommendation

While 6 years is the legal minimum, many accountants recommend keeping records for at least 7 years as a safety buffer. HMRC can open enquiries into returns for up to 6 years (or 20 years in cases of fraud or deliberate behaviour), so having records readily available is important.

Filing your CT600 is easier when your records are in order. Taxpipe's step-by-step process helps you work through your return methodically — file online from just £59. Start your CT600 →

Digital Record Keeping

The days of shoeboxes full of receipts are numbered. HMRC increasingly expects — and in some cases requires — digital records.

Making Tax Digital (MTD) for Corporation Tax

HMRC is rolling out Making Tax Digital for Corporation Tax, which will eventually require most companies to:

• Keep their accounting records digitally
• Use MTD-compatible software to maintain those records
• Submit tax information to HMRC through a digital link from their software

MTD for Corporation Tax is expected to come into effect from 2026 onwards for larger companies, with smaller companies following. While exact timelines are still being confirmed, the direction is clear: digital record keeping will be mandatory.

For the latest on what's coming, read our guide on Making Tax Digital for Corporation Tax.

Acceptable Digital Formats

Even before MTD becomes mandatory, HMRC accepts digital records. Acceptable formats include:

• Cloud accounting software (Xero, QuickBooks, FreeAgent, etc.)
• Spreadsheets (Excel, Google Sheets) — provided they're properly maintained
• Scanned copies of original documents — provided they're legible and complete
• Digital photos of receipts — commonly used with expense apps
• PDF invoices — increasingly the standard
• Email records — where they contain relevant financial information

Requirements for Digital Records

If you keep records digitally, HMRC requires that:

1. Records are legible — scans and photos must be clear enough to read all relevant details
2. Records are complete — a scan of just the total isn't sufficient; the full document must be captured
3. Records are secure — backed up and protected against loss, damage, or unauthorised access
4. Records are accessible — you must be able to produce them if HMRC requests them
5. Original records can be destroyed after scanning only if the digital copy is a complete and accurate reproduction

Cloud Storage Best Practices

HMRC's Powers to Inspect Records

HMRC has extensive powers to request and inspect your company's records. Understanding these powers helps you prepare and respond appropriately.

Information Notices

HMRC can issue information notices requiring you to produce records. There are three types:

1. Taxpayer Notice (Section 8 TMA 1970) Requires the company to produce documents or provide information. This is the most common type and is usually issued as part of a compliance check.

2. Third Party Notice (Section 8A TMA 1970) Issued to third parties (your bank, your accountant, your customers) requiring them to provide information about your company's affairs. You'll normally be notified, though in exceptional cases HMRC can obtain third-party notices without telling you.

3. Identity Unknown Notice Used when HMRC suspects tax irregularities but doesn't know which specific taxpayer is involved — for example, requesting records from a bank about all accounts matching certain criteria.

What HMRC Can and Cannot Demand

HMRC can request:

• All records listed in the "What Records Must You Keep" section above
• Underlying workpapers and calculations
• Correspondence related to financial transactions
• Electronic records in their original digital format
• Access to accounting software data

HMRC cannot request:

• Legally privileged documents — communications between you and your solicitor for the purpose of obtaining legal advice about your tax affairs
• Tax advisers' papers — your accountant's own working papers (as opposed to your records held by the accountant) — though this protection has limits
• Documents not in your possession or power — you can't be required to create new documents, only to produce existing ones

HMRC Inspection Visits

In addition to written requests, HMRC has the power to visit your business premises to inspect records. This can happen:

• As part of a scheduled compliance check (usually with advance notice)
• Unannounced, if HMRC believes there's a serious risk of evidence being destroyed

For a scheduled visit, HMRC will give you at least 7 days' notice. You have the right to:

• Suggest an alternative date (within reason)
• Have your accountant or tax adviser present
• Ask HMRC to explain what they're looking for
• Provide records electronically rather than in paper form

For more on what happens during an HMRC enquiry, see our guide to HMRC enquiries into your CT600.

Penalties for Inadequate Record Keeping

HMRC can impose penalties if you fail to keep (or preserve) adequate records.

The Penalty Structure

The maximum penalty for failure to keep adequate records is £3,000 per accounting period. HMRC applies this on a sliding scale:

How Penalties Are Triggered

Record-keeping penalties are usually imposed during or after an HMRC compliance check, when HMRC discovers that:

• Records were insufficient to verify the CT600 return
• Records were destroyed before the 6-year retention period expired
• The company couldn't produce records when requested

Beyond Penalties: The Practical Impact

Poor record keeping causes problems beyond formal penalties:

• HMRC may estimate your tax — if you can't support the figures on your CT600, HMRC will make their own estimate, which is rarely in your favour
• Lost expense claims — without receipts and records, you can't claim allowable deductions, meaning you pay more tax than necessary
• Failed capital allowances claims — you need documentation to support every item in your capital allowances pools
• Longer and more intrusive HMRC enquiries — if HMRC finds gaps, they'll dig deeper
• Difficulty in selling the company — any buyer will want to review years of clean financial records

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Practical Record Keeping Tips

1. Separate Business and Personal

The single most important step. If you're using personal bank accounts or credit cards for business expenses, it becomes exponentially harder to maintain clean records. Use:

• A dedicated business bank account for all company transactions
• A business credit card for business purchases
• A separate PayPal/Stripe account for online transactions

2. Record Transactions Weekly (Not Yearly)

The biggest record-keeping failures happen because directors leave everything until year-end. By then, receipts are lost, bank transactions are unrecognised, and expense categories are guesswork.

Set aside 30 minutes per week to:

• Categorise bank transactions
• Photograph and file receipts
• Record any cash expenses
• Note any unusual transactions

3. Use the Right Tools

You don't need expensive software to keep good records. Options include:

4. Photograph Every Receipt Immediately

Use your phone to photograph receipts on the day you receive them. Thermal receipts (the shiny paper from card machines) fade within months. Many accounting apps have built-in receipt scanning.

5. Maintain a Mileage Log

If you claim business mileage, HMRC expects a contemporaneous log showing:

• Date of journey
• Destination and purpose
• Miles driven
• Opening and closing odometer readings (ideal but not always required)

An app like MileIQ or a simple spreadsheet works fine.

6. Keep Board Minutes for Financial Decisions

HMRC may want to see evidence that financial decisions were properly authorised. Keep minutes for:

• Dividend declarations
• Director's loan approvals
• Major purchases or disposals
• Changes to remuneration
• Year-end stock valuations

7. Reconcile Monthly

Compare your accounting records to your bank statements every month. Catch discrepancies early, not at year-end when the trail is cold.

8. Back Up Everything

Whatever your record-keeping method, ensure you have at least two copies stored in different locations. Cloud storage with automatic backup is ideal. A local backup (external hard drive) provides additional protection.

Records for Specific CT600 Areas

Certain areas of the CT600 require particular attention to record keeping:

Capital Allowances

You need to maintain:

• A fixed asset register listing every asset, its cost, date of purchase, and category
• Invoices and receipts for every asset purchased
• Disposal records for assets sold or scrapped
• Pool calculations showing how annual allowances are computed

Our guide on capital allowances and corporation tax explains the claims process in detail.

Research and Development (R&D) Claims

R&D tax relief claims are heavily scrutinised by HMRC. You need:

• Project descriptions explaining the scientific or technological uncertainty
• Time records showing how much time qualifying staff spent on R&D
• Cost breakdowns for staff, materials, subcontractors, and software
• Technical narratives explaining what advances you sought

Losses

If you're carrying forward or carrying back losses, maintain:

• Records of the accounting period in which the loss arose
• The computation showing how the loss was calculated
• Records of how the loss has been used — which periods it was set against and how much remains
• Your CT600 loss claims from previous years

Group Relief

For companies claiming or surrendering group relief:

• Group structure diagrams showing the relationship between companies
• Agreements between companies for the surrender/claim of losses
• Calculations showing the amount of relief claimed
• Evidence of payment if the claiming company pays for the surrendered losses

What Happens If You Lose Records

If records are accidentally destroyed (fire, flood, theft, computer failure), you should:

1. Notify HMRC immediately — explain what happened and what records were lost
2. Reconstruct what you can — bank statements can be obtained from your bank, purchase invoices from suppliers, sales records from customers
3. Document your reconstruction efforts — show HMRC you've made a genuine effort
4. Use estimates where necessary — but clearly flag them as estimates in your accounts and CT600

HMRC is generally understanding about genuine accidental loss, especially if you can demonstrate you had good systems in place and made efforts to reconstruct records. What they don't tolerate is deliberate destruction or carelessness (e.g., never keeping records in the first place).

Frequently Asked Questions

How long do I need to keep corporation tax records?

You must keep records for 6 years from the end of the accounting period they relate to. However, if you filed your return late, the period extends to 6 years from the filing date. If you have ongoing loss claims or capital allowances, keep the underlying records until those claims are no longer relevant — which could be much longer than 6 years.

Can I keep digital copies instead of paper originals?

Yes — HMRC accepts digital copies (scans, photographs) of original documents, provided they are legible, complete, and securely stored. Once you have a satisfactory digital copy, you can destroy the paper original. However, ensure your digital copies include all relevant details (dates, amounts, VAT numbers, supplier details) and are stored with proper backups.

What records do I need for my CT600 filing?

At minimum, you need: annual accounts (profit and loss, balance sheet), bank statements, sales and purchase invoices, payroll records, capital asset records, dividend documentation, director's loan account records, and your corporation tax computation. The exact requirements depend on your company's activities — see our CT600 filing checklist for a comprehensive list.

Can HMRC penalise me for records I never had?

Yes. The obligation is to keep adequate records, which means creating and maintaining them from the outset. "I never recorded that" is not a defence — it's the problem. HMRC can impose penalties of up to £3,000 per accounting period for failure to keep adequate records, whether the failure was deliberate or careless.

What should I do if HMRC requests records I can't find?

Respond to HMRC promptly and honestly. Explain what's missing and why, and provide whatever alternative evidence you can (bank statements, supplier confirmations, etc.). Cooperating fully is essential — HMRC views obstruction or delay very negatively and may increase penalties. If the missing records relate to a significant tax claim, consider getting professional advice before responding.

Summary

Corporation tax record keeping isn't glamorous, but it's fundamental to running a compliant UK company. The key principles:

• Keep everything — invoices, receipts, bank statements, contracts, board minutes
• Keep it for 6 years minimum (longer for losses and capital allowances)
• Go digital — MTD is coming, and digital records are easier to manage, search, and back up
• Stay organised — weekly maintenance prevents year-end chaos
• Be ready for HMRC — they have broad powers to inspect, and cooperation is always the best strategy

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Related Reading

• Dormant Company CT600 Filing: Do You Still Need to File? (Yes — Here's How)
• Sole Trader vs Limited Company: Full Tax Comparison (2025/26)
• Making Tax Digital for Corporation Tax: What Your Company Needs to Know