HMRC has issued a reminder to company directors and accountants to file CT600 company tax returns on time to avoid delays at the tax authority, and to ensure loss relief claims are submitted correctly.

To help process tax returns ‘without delay’, it is essential to ensure that the start and end dates of the return period for the filing are correct and match the company’s accounting period structure, HMRC said.

The deadline for tax returns is 12 months after the end of the accounting period it covers, and if the submission is late, HMRC charges a penalty for late filing. Corporation tax bills need to be paid by a late date, usually nine months and one day after the end of the accounting period.