Corporation Tax: claims for an earlier period and payment reference numbers
Repayments due for an earlier accounting period
If you’re claiming a loss carry back that reduces your Corporation Tax liability for an earlier accounting period, please remember to complete the repayment for an earlier period box on the CT600 form. This will allow HM Revenue & Customs (HMRC) to process your claim and make any appropriate repayment to you. If you’ve previously given HMRC your bank account details to enable repayments by Bacs, please remember to update them if they change.
Using the right payment reference
When you make a Corporation Tax payment to HMRC, you must use the correct 17 character payment reference number. This tells HMRC which accounting period to set your payment against. If you use the wrong reference, or only use the 10 digit Unique Taxpayer Reference (UTR), HMRC may not allocate your payment correctly and you may get further payment reminders, or the payment may be automatically refunded to you. You’ll also need to change any payment reference stored by your bank for an earlier bank transfer when you make a payment for a different accounting period.