From April 2027, it will be mandatory to file amendments to company tax returns online within standard time limits, affecting the 3.2 million businesses which currently submit corporation tax returns.

Mandatory electronic filing of amendments to returns will be implemented from 1 April 2027.

HMRC said: ‘This change will be extensively communicated prior to this date. Companies submitting amendments to returns via correspondence after this date will be asked to submit their amended return online.’

Plans for exceptions are currently out for consultation, as well as feedback on the proposed start date as part of HMRC’s programme to modernise and standardise company tax returns.

Exceptions to online amends