Company Tax Returns
Making changes
You must usually make any changes (‘amendments’) within 12 months of the filing deadline.
You can:
- use commercial software
- use HMRC’s free online filing service, if you sent your return this way
- write to or send a paper return to the Corporation Tax office
HMRC may check for errors in your Company Tax Return.
HMRC may charge you a penalty for errors.
Making changes more than 12 months after the filing deadline
If you have overpaid Corporation Tax you may still be able to claim it back. You can find out if you should claim overpayment relief and how to make a claim.
If you have underpaid Corporation Tax you should tell HMRC using the online disclosure service as soon as possible.