Guidance

Find out how to use the Self Assessment for Agents online service

Find out what the Self Assessment for Agents online service is for, what you can do in the service and how to do it.

The Self Assessment for Agents online service covers individuals, businesses, trusts and partnerships. Client authorisations also cover National Insurance and, for individuals, requests for information to help calculate the High Income Child Benefit charge.

To use the Self Assessment for Agents online service you’ll need to:

  • have an agent code
  • be registered with HMRC online services
  • add the Self Assessment for Agents service to your portfolio
  • set up agent authorisation for each of your clients

You must register for the Self Assessment for Agents online service whether you plan to use HMRC online services or commercial software to send your clients’ tax returns.

Once you are authorised on behalf of your client, HMRC will send letters and forms directly to you, including your client’s Self Assessment statements (SA300) and any fixed automatic penalty notices (SA328). You’ll also be able to view your client’s account online along with any statements of account.

What you can do in the service

You can use the Self Assessment for Agents online service to:

  • view your Self Assessment client’s PAYE coding notice
  • view your client’s Self Assessment statements
  • view the tax liabilities and the payments a client has made
  • make claims to reduce your client’s payments on account
  • submit your client’s tax returns online
  • view and change your client’s contact details online
  • download your full client list

View PAYE coding notices

You can view your clients’ PAYE coding notices online if:

  • the PAYE coding notice was issued on or after 11 October 2011
  • you were authorised to act on behalf of the client for Self Assessment (form 64-8 or online agent authorisation was in place) at the time the notice was issued

If your client previously had an agent who was registered for the Self Assessment for Agents online service, or if your client was registered for the service in their own right at the time the coding notice was issued, you may be able to view any notices issued on or after 11 October 2011, even if you became their authorised agent at a later date.

You’ll also be able to view PAYE coding notices for the:

  • current tax year
  • previous tax year
  • next tax year

Coding notices are usually available to view online 72 hours after they’re issued.

Send online tax returns for your client

When you send your client’s tax return online using Self Assessment for Agents you can use either:

  • HMRC free online service
  • commercial software

How to use the service

You can use HMRC online services to send the main Self Assessment tax return form SA100 and most supplementary pages. The online service checks the return as you complete it and does the tax calculations for you.

You can also get free technical support from the online services helpdesk.

Commercial software

You can use commercial software to send your client’s tax return online. Commercial software also allows you to file the partnership return (form SA800) and the trust return (form SA900) as well as other Self Assessment forms.

HMRC provides a list of Self Assessment commercial software suppliers whose software has been tested to make sure it’s compatible with HMRC systems.

Commercial software for other HMRC online systems is also available.

If you’re a new tax agent

If you’re going to be using the Self Assessment online service as a tax agent, you must first register with HMRC. Check which steps you must take before registering as a tax agent.

Published 1 January 2014
Last updated 5 May 2022 + show all updates
  1. The list under 'How to get an agent code' has been updated to include a VAT registration number (if applicable) and a PAYE Employer reference (if applicable).

  2. More information has been added to the section about how to get an agent code.

  3. Section 'How to get an agent code' has been updated to advise if HMRC is your anti-money laundering supervisor to provide your registration code and if you are supervised elsewhere to provide evidence confirming supervision of your accountancy services.

  4. The regulation name in section 'How to get an agent code' has been updated to The Money Laundering Terrorist Financing and Transfer of Funds Regulations 2017.

  5. Agent online services guidance has been updated to improve style and layout of content. HMRC Online Services log in information also updated in this guide.

  6. First published.