How to register your client for a tax service as an agent
Find out how to register your client for Self Assessment, Corporation Tax, PAYE, VAT or their trust or estate.
- From:
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HM Revenue & Customs
PublishedPublished:- 6 October 2022
- Last
updatedupdated: -
25- 8
NovemberSeptember20222026 —See all updates - 8
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 Onlineonline Servicesservices account.
What you’ll need
You’ll need:
- your Government Gateway user ID for HMRC
OnlineonlineServicesservices - a Self Assessment or Corporation Tax agent code (even if you’re registering for PAYE)
How to register
Sign into your HMRC
OnlineonlineServicesservices account using your Government Gateway user ID.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 your client is self-employed
If you want to register:
- a nominated partner or new partnership, use form SA400
- a partner in a partnership, use form SA401
- partners who are not individuals, use form SA402
If your client is not self-employed
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 their:
- full name
- postal address (this can be outside of the UK)
- date of birth
- daytime telephone number
- UK National Insurance number, if they have one
Fill in and send the form online
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.
If you cannot send the form online
You can fill in the form online, then print and post the form to HMRC.
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Get all information together before you start. You will fill this form in online and you cannot save your progress.
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Fill in form SA1.
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Print and post it to HMRC, using the postal address shown on the form.
This file may not be suitable if you use assistive technology (such as a screen reader). If you need a more accessible format, email different.format@hmrc.gov.uk and tell us what format you need. It will help if you tell us what assistive technology you use. Read the accessibility statement for HMRC forms.
Registering your client’s trust or estate
If you want to register your client’s trust or estate, you can do so through your agent services account.
You can also find out more about howregistering toa register your client’s trust online and how to register your client’s estate online.
What you’ll need
You’ll need your Government Gateway user ID for your agent services account.
How to register
Sign into your agent services account using your Government Gateway user ID.
Go to ‘Trusts and estates’.
Select either
‘registered‘register the trust’ or ‘estate’.Follow the instructions on screen.
Registering your client for VAT
To register a client for VAT, you must have a Government Gateway user ID and password for either:
- agent services account
- HMRC
OnlineonlineServicesservices
If you register for VAT using your Government Gateway user ID for HMRC Onlineonline Services,services, you may be asked for details to verify your own identity, such as:as your:
yourNational Insurance number- date of birth
- passport or driving licence
You will not be asked to provide this information using your Government Gateway user ID for your agent services account.
What you’ll need
You’ll need:
- your Government Gateway user ID and password for either your agent services account or HMRC
Onlineonline services account - your name
- your phone number
- your email address
- your client’s name
- your client’s date of birth
- details of your client’s turnover and nature of business
- your client’s bank account details (if available)
- your client’s National Insurance number
- a form of
IDidentification from your client (such as their passport or driving licence) - your client’s Corporation Tax
Payments,payments, PAYE,Self-AssessmentSelfReturn,Assessment return, recent payslip or P60 (whichever is most appropriate)
If you’re registering a limited company client, they must have a Company Registration Number and a Corporation Tax Unique Taxpayer Reference (UTR) to complete the VAT registration process.
Individuals and partnerships do not need to have a Self Assessment UTR to register for VAT, but if they do, you must supply this. You’ll be asked to verify the entity you are registering, therefore you should know some of the history of the business or person you’re registering.
How to register
Register your client by signing in with your Government Gateway user ID for either your agent services account or HMRC
Onlineonline services.On the screen ‘Whose business do you want to register?’ select ‘Someone else’s’ (unless you’re registering your own agency).
Follow the instructions on screen.
Updates to this page
Explore the topic
Update history
2026-09-08 14:12
Guidance on how to register your client for Self Assessment if they are not self-employed has been updated.
2022-11-25 14:08
Page updated with information on what you’ll need when registering your client for VAT, including registering limited company clients and individuals and partnerships.
2022-10-06 14:56
First published.