Use your accounts office reference when you make PAYE payments or contact HMRC about a payment.
Your accounts office reference is printed on the new employer registration letter HMRC sent you when you first registered as an employer.
It can also be found on the front of the payment booklet if you receive one, or on the ‘Paying Electronically’ letter issued instead of the booklet.
It can also be found on most demands issued by HMRC. It is 13 characters long and will be in a similar format to this example: 123PA00012345
It is important that you show your reference number with no gaps between the characters, otherwise it could delay the payment reaching your account.