Corporation Tax enquiry document checklist

A Corporation Tax enquiry document pack should connect the company return and tax computation to accounts, ledgers and supporting transactions. Use the company’s accounting periods and legal entity details rather than the personal tax-year timetable used for Self Assessment.

Flag director transactions, connected-party matters and material adjustments. Keep the original filed computation and a clear record of any later correction.

Confirm the company and accounting periods

Check the company's legal name, tax reference and the accounting periods specified in the enquiry. Keep the opening letter, submitted Company Tax Return, accounts and computation for each period together. HMRC's compliance-check guidance includes Company Tax Returns and accounts among the records it may examine. ^[1] Do not assume that a group's trading name identifies the legal entity whose return is under review.

Prepare an entity map if the company has subsidiaries, connected businesses or shared finance functions. Identify where each company's records are held and who can explain intercompany transactions. This is a practical navigation tool, not a substitute for the individual accounting records. It helps prevent invoices or bank statements from a related company being supplied as though they belonged to the taxpayer named in the notice.

Connect the accounts to the tax computation

Build a reconciliation from the approved accounts to the Corporation Tax computation and submitted return. Identify adjustments to accounting profit, supporting schedules and any losses or reliefs claimed. Each material figure should lead to a working paper and then to source evidence. A copy of the annual accounts alone may not explain how a particular expense or balance was treated for tax purposes.

Keep the submitted version distinct from later management accounts or amended calculations. If the accounts were revised, explain when and why, and identify which version supported the return under enquiry. Preserve audit or review adjustments where relevant to understanding the figures, with appropriate professional review of any protected material. Avoid silently replacing an old computation with a new spreadsheet that conceals the original calculation history.

Gather evidence around the queried transactions

For expenditure questions, collect invoices, contracts, payment evidence and a factual explanation of the business purpose. For income differences, reconcile customer records and ledger entries to the accounting period concerned. For asset-related questions, preserve purchase documents, disposal records and the schedules used in the tax calculation. Tailor the pack to HMRC's actual questions rather than using an indiscriminate download of every finance folder.

Where directors, shareholders or connected companies are involved, describe the transaction and the parties accurately. Identify approvals and agreements without treating a board minute as proof that every tax consequence was considered. If the purpose or terms are unclear, ask the people involved and record the basis of their explanation. Mark recollections as such until they can be supported by documents.

Control missing records and formal requests

Use an evidence tracker to identify documents held by former staff, outsourced providers or previous accountants. Record requests for replacements and expected delivery dates. If a formal information notice has been issued, assess its requirements and timing with the adviser. HMRC's notice guidance addresses information obligations, limitations and consequences of inaccurate or missing responses. ^[2] Do not assume an internal difficulty automatically extends the deadline.

Keep originals unchanged and label reconstructed schedules with their preparation date and source material. Review confidentiality and any legal privilege issue before disclosure through the appropriate specialist. Preparing records for an HMRC enquiry explains how to prepare a question-led evidence pack. The company should be able to show what each document answers, which calculations were checked and which points remain genuinely unresolved.

Agree corporate approval and submission ownership

Nominate the finance contact who can confirm factual statements and the adviser responsible for communicating with HMRC. Agree how draft responses will be approved and who monitors the case when key staff are unavailable. A director signing off a response should have a clear summary of the figures and uncertainties, not only a large attachment bundle with an instruction to approve it urgently.

For assistance organising a Corporation Tax enquiry file, see HMRC enquiry response support. Provide the opening letter, periods under review and the nearest response date. Explain whether the original return preparer remains involved and whether specialist tax or legal advice is already being obtained. This allows the work to be scoped around the company's actual evidence and representation needs.

After submission, save an exact copy of the response and its index, together with delivery evidence. Update the tracker for follow-up questions and any agreed additional documents. Keep the eventual adjustments connected to the original accounting periods so later accounts, loss schedules and returns can be reviewed consistently without guessing how the enquiry outcome changed the company's tax position.

Illustrative scenario

A company is asked about a deduction in its computation. The adviser traces it to the accounts adjustment and underlying agreement, preserving the approval and payment evidence.

Preparation checklist

• Confirm the company period
• Retain the filed computation
• Link adjustments to evidence
• Identify connected-party questions