How to Obtain an Agent Code for Corporation Tax or Self-Assessment

You will need an agent code to register each of these services on your HMRC online services account and access the services to transact.

To obtain a code for corporation tax or self-assessment, you must request it in writing. These services are not linked, you must request an agent code for each tax service.

What you will need

In your application, you will need to include:

  • your full name
  • your business name (if different)
  • the address from which your activities are carried out (this cannot be a PO box address)
  • Your phone number
  • Your email address
  • your supervisor for the purposes of the Money Laundering Regulations 2017
  • your anti-money laundering surveillance registration number if HMRC is your anti-money laundering supervisor
  • other documentary evidence confirming the supervision of your accounting services if you are supervised elsewhere for anti-money laundering purposes, for example by a professional body – check with your supervisor if you are unsure of the evidence to provide (HMRC will not register you as an agent until you provide this evidence)
  • your national insurance number
  • your unique self-assessment taxpayer reference (UTR) (you must provide it if you are an administrator with a UTRsole proprietorship or partner)
  • your partnership UTRlimited liability company UTR or company UTR (if applicable)
  • your business registration number (if applicable)
  • your VAT registration number (if applicable)
  • your employer’s PAYE reference (if applicable)
  • details of any taxes you plan to process (e.g. self-assessment)

If your business has multiple partners or directors, you will also need to include all of their:

  • full names
  • National Insurance Numbers
  • Self evaluation UTR

Your application will be rejected if you do not provide all of this information or if HMRC is not reasonably satisfied with the information you have provided.

where to send it

Mail your Agent Code request to the Agent Maintenance team at:

National insurance contributions and employer’s office

HM Revenue and Customs



HMRC will tell you within 28 days of receiving your application whether or not it has been accepted.

If you lose your agent code, you must write to the agent maintenance team.

When you have your agent code

Once you have received your agent code in the post, log on to HMRC’s online services to register the tax service you want on your account.

Posted on September 7, 2022

Luisa D. Fuller