HMRC can be called by phone on 0300 200 3410 for help with general Corporation Tax enquiries. You will need your 10-digit Unique Tax Reference (UTR) when calling HMRC and this reference number cannot be provided over the phone.

The UTR is the primary identifier for a company and should be used whenever HMRC is contacted. The number can be found on all letters from HMRC and also in HMRC’s business tax account portal – if the company has registered for online tax services and attached the UTR to their profile.

HMRC’s Corporation Tax phone lines are open Monday to Friday: 8am to 6pm and closed weekends and bank holidays. The phone lines are typically less busy between 8.30am and 11am.

You can also write to HMRC at the following address for help with general Corporation Tax enquiries.

Corporation Tax Services
HM Revenue and Customs
BX9 1AX
United Kingdom

You should include your UTR in the letter and on the first page of any documents you send. If you are replying to a letter you’ve received about your Corporation Tax, you should use the address on that letter.