Final CT600 guide

Final-period CT600 filing before strike off or dissolution.

A practical guide for directors and accountants closing a UK limited company, preparing final accounts, settling Corporation Tax, and keeping HMRC filing evidence.

Closing a company does not remove the CT600 problem

A company that stops trading may still need to file Company Tax Returns and pay Corporation Tax while it is closing down. GOV.UK guidance for strike off says final statutory accounts and a Company Tax Return must be sent to HMRC, with the return stating that the accounts are final trading accounts and that the company will soon be struck off.

For directors, the practical risk is timing. The company wants a clean closure, but HMRC still needs the final Corporation Tax position. For accountants, the file needs enough evidence to show final accounts, tax computation, payment, and dissolution steps were coordinated.

The final-period workflow

  • Confirm the company has stopped trading or is about to stop trading.
  • Prepare final accounts for the period ending at cessation or the relevant closure date.
  • Prepare the Corporation Tax computation and CT600 for the final trading period.
  • Include iXBRL accounts and computations where required for online filing.
  • State clearly that the accounts are final trading accounts where appropriate.
  • Pay Corporation Tax and any other outstanding tax liabilities.
  • Preserve HMRC submission evidence before the company is dissolved.

Strike off, liquidation, and stub periods

The CT600 position depends on how the company is closing. Voluntary strike off, members' voluntary liquidation, and other winding-up routes can create different accounting-period and filing questions. HMRC guidance says winding up normally ends the current Corporation Tax accounting period and begins a new one.

HMRC's online filing guidance also discusses end-of-life cases where a company asks HMRC to agree to strike off before a statutory filing date for the last normal accounting period, and where there may be a stub period after the last normal period. That means the closure file needs to capture correspondence and the basis used for settling the tax position.

Final accounts are not just Companies House accounts

GOV.UK strike-off guidance says final statutory accounts and a Company Tax Return go to HMRC, and that final accounts do not have to be filed with Companies House for the strike-off step. In practice, the accountant still needs to prepare the final figures, tax computation, and any iXBRL attachments needed for HMRC online filing.

Do not leave the CT600 to the end of the closure process. It is often the document that proves the company's final tax affairs have been dealt with.

Common closure traps

  • Applying for strike off before Corporation Tax, VAT, payroll, or other tax positions are settled.
  • Ignoring gains or balancing charges on assets sold before closure.
  • Missing director loan, dividend, or payroll balances in the final accounts.
  • Not preserving HMRC acknowledgements before the company is dissolved.
  • Assuming a dormant company has no HMRC filing obligation without checking notices to deliver a return.
  • Letting refunds or company bank balances remain after dissolution, creating bona vacantia risk.

Evidence to keep before dissolution

  • Final accounts and tax computation.
  • Submitted CT600 and iXBRL attachments.
  • HMRC acknowledgement or rejection response.
  • Corporation Tax payment evidence or nil-to-pay confirmation.
  • Client/director approval of the final return.
  • Companies House strike-off or liquidation documents.
  • Any HMRC correspondence about early strike off, stub periods, or settlement basis.

How Robocount supports final-period CT600 work

Robocount helps keep the final-period return package structured: CT600, computation, iXBRL attachments, approval record, payment follow-up, and HMRC submission evidence. That is especially useful where the director is trying to close a company without losing the audit trail.

  • Supports final-period CT600 preparation and review.
  • Keeps iXBRL attachments and computation checks in the same workflow.
  • Helps practices preserve submission and approval evidence before dissolution.
  • Gives directors a clearer route from final accounts to HMRC filing.
  • Supports API and AI-assisted workflows where closure cases need structured status checks.

FAQ

Do I need a CT600 if I am striking off my company?

GOV.UK guidance says you must send final statutory accounts and a Company Tax Return to HMRC when closing down a company for strike off. The facts and HMRC notices matter, so check the company's position before filing.

Do final accounts need to be filed with Companies House?

GOV.UK strike-off guidance says final accounts do not have to be filed with Companies House for that step, but final accounts and the Company Tax Return still need to be sent to HMRC.

Can a dissolved company deal with HMRC later?

Once a company is dissolved, it no longer exists as a legal entity. That is why submission evidence, payment records, and remaining assets should be dealt with before dissolution.

Useful official references

This guide is general product and filing workflow information, not legal or tax advice. Check current HMRC and Companies House guidance before closing a company.