Dealing with HMRC – guidance

Agent authorisation: apply using HMRC Online Services

How to set up authorisation online to deal with HM Revenue and Customs (HMRC) on a client’s behalf.


If you act as a tax agent or adviser, you must have formal authorisation to deal with HMRC on your client’s behalf.

The easiest way to do this is online. You and your client can set up the authorisation securely by using HMRC Online Services.

You’ll need an agent code or reference number from HMRC for each type of agent authorisation. Make sure you have this before you attempt to set up authorisation online.

HMRC Online Services: how to set up agent authorisation

You’ll need to register as an agent in HMRC Online Services and enrol for each service you need to use.

Once you’ve done that, your clients can authorise you to act on their behalf for each service.

The services are:

Once you’re authorised, you can use HMRC Online Services to:

  • manage your client lists
  • file returns
  • update a client’s details
  • receive information about your client from HMRC

You can also contact HMRC by phone or post on behalf of your client.

Online administrators and assistants

The first person to set up your agent online account will automatically be set as an ‘administrator’.

The administrator can set up other administrators or assistants on your agent account by logging into the Government Gateway and choosing ‘add an administrator’ or ‘add an assistant’.

You can use this to manage your client lists and split work across your organisation, for example you can set up more than one client list and allocate them to different administrators or assistants.

What administrators can do

Administrators can perform tasks online on behalf of your organisation. They can:

  • access an online service your organisation is enrolled for
  • enrol for and de-enrol from online services
  • set up or delete other administrators
  • set up or delete online assistants
  • assign services to other administrators or assistants
  • change their own registration details - password, user name or email address

What assistants can do

Assistants must be set up by your organisation’s administrators. They can only access services assigned to them by an administrator. Assistants can:

  • access an online service your organisation is enrolled for - if an administrator has assigned the service to them
  • change their own registration details - password, user name or email address

If you can’t set up agent authorisation online

It’s easiest to set up your authorisations as an agent online, but if you can’t you’ll need to get your client to complete one of HMRC’s paper authorisation forms.

You can’t set up agent authorisation online for:

  • tax credits clients
  • individuals who aren’t under Self Assessment
  • Self Assessment clients who have a British Forces Post Office address

You’ll need to use the paper forms for these clients.