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.
Corporation Tax deadline tool
Corporation Tax Payment Deadline Calculator
Calculate the standard Corporation Tax payment deadline from the accounting period end date using the normal 9 months and 1 day rule.
This tool is for the standard payment regime and does not cover quarterly instalment payment cases for large companies.
Corporation Tax Payment Deadline Calculator
Calculate the standard Corporation Tax payment deadline from the end of the accounting period.
What this date means
The result is the standard Corporation Tax payment deadline based on the accounting period end you enter.
It helps with basic deadline planning when you are not in the large-company instalment regime.
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.
Rule used by this tool
For companies within the standard payment regime, Corporation Tax is normally due 9 months and 1 day after the end of the accounting period.
Worked examples
How the result behaves in practice
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.
Turn the result into an action plan
Confirm that the company is not within a quarterly instalment regime before relying on the date.
Use the related late-payment penalty and interest tools if payment may miss the standard deadline.
Add the date to the wider compliance calendar so the payment deadline stays visible alongside filing work.
Read the guide
Corporation Tax payment deadlines
Understand the standard Corporation Tax payment deadline and why it should be tracked separately from the return-filing date.
Assumptions and limits
This tool applies a published rule set directly and is designed for standard scenarios.
Assumptions
- You are calculating for the standard Corporation Tax payment regime.
- The accounting period end date is the correct end date for the relevant period.
Limits and rule basis
- This tool does not cover instalment payment rules for large companies.
- It does not determine the tax amount due or whether interest applies.
- HMRC guidance on paying Corporation Tax (verified 2026-03-09)