The deadline for submitting your corporation tax return is 12 months after the end of the accounting period it covers.
Your corporation tax is payable 9 months and 1 day following the end of the accounting period it relates to.
| Time after your deadline | Penalty |
| 1 day | £100 |
| 3 months | Another £100 |
| 6 months | HM Revenue and Customs (HMRC) will estimate your Corporation Tax bill and add a penalty of 10% the unpaid tax |
| 12 months | Another 10% of any unpaid tax |
If your return is late 3 times in a row the penalties increase to £500 each.