How to register your client for a tax service as an agent

Registering your client for Self Assessment, Corporation Tax or PAYE

If you want to register your client for any of these taxes, you can do so through your HMRC online services account.

Select ‘Register for HMRC taxes’ in the left-hand menu.

Select ‘Register for HMRC taxes’ on the right.

Select the first option ‘I want to tell HMRC that my client is in business and needs to register for a new tax or tell HMRC that the company is now active’.

Read the guidance on the following screens and select ‘Next’.

Select the tick box for the tax you want to register for and enter your client’s name or a client reference.

Follow the instructions on screen and submit.

How to register your client for Self Assessment if you cannot use the online service

You can also use the online form CWF1 or the paper version of form CWF1 to register your client for Self Assessment and National Insurance contributions. You’ll need your client’s National Insurance number.

If you want to register a client that is not self-employed or a director, you’ll need to use form SA1.

You’ll need to sign in to use the form. If you do not already have sign in details, you’ll be able to create them.

You can fill in the form online, then print and post the form to HMRC.

Get all information together before you start. You will fill this form in online and you cannot save your progress.

Print and post it to HMRC, using the postal address shown on the form.