Why must I compete two corporation tax returns for my company’s first financial year?

HMRC require that all companies’ financial years finish on the last day of the month in which they are incorporated. HMRC also want any one corporation tax return to cover no more than 365 days. This means companies must submit one return covering the twelve months to the anniversary of the incorporation, and a second taking them to the end of their anniversary month.


For example, let’s say you started your limited company on 15 September 2020. At the end of 30 September 2021, you file just company accounts to for one period from 15 September 2020 to 30 September 2021. However, you will have to file two corporation tax returns: one running from 15 September 2020 to 14 September 2021, and another from 15 September 2021 to 30 September 2021. From the then onwards, your company’s financial year will run from 1 October to 30 September every year, and you only need to file one company account and one corporation tax return each year.