Practical guide

Corporation Tax payment deadlines

Understand the standard Corporation Tax payment deadline and why it should be tracked separately from the return-filing date.

Payment date versus return date

The standard Corporation Tax payment date usually arrives earlier than the CT600 filing deadline, which is why businesses often need both dates visible at once.

If those dates are mentally merged together, one of them usually drifts.

Rule summary

Standard Corporation Tax payment rule

For companies within the standard payment regime, Corporation Tax is normally due 9 months and 1 day after the end of the accounting period.

Large-company instalment-payment cases sit outside this standard rule and are not covered by this calculator.

Worked examples

How the rule behaves in practice

  • Standard payment regime: Enter the accounting period end for a company that pays Corporation Tax under the ordinary single-payment rule. The calculator returns the standard due date 9 months and 1 day later.
  • Deadline planning before interest risk: Use the calculator as the starting point before checking what happens if payment slips beyond the due date. The result gives the anchor date for late-payment penalty and interest checks.

Practical consequences

  • A missed payment date can lead to interest and penalty questions even where the return itself is not yet due.
  • That makes deadline clarity one of the simplest ways to avoid turning a tax obligation into a recovery workflow.

Important limits

  • This tool does not cover instalment payment rules for large companies.
  • It does not determine the tax amount due or whether interest applies.

Turn the result into an action plan

  • Use the payment calculator to anchor the date first.
  • Open the late-payment penalty or interest tools if the date has already slipped.
  • Track the payment date in the same calendar as the CT600 filing deadline.

Use the tool

Corporation Tax Payment Deadline Calculator

Calculate the standard Corporation Tax payment deadline from the end of the accounting period.

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