Agent authorisation and form 64-8

Which method for which tax

The digital handshake

1. Start the request

   Sign in to the agent services account and choose "Ask a client to authorise you" (GOV.UK).

2. Send the link

   Enter the client's details and copy the authorisation request link from the final page. Send it to the client.

3. The client accepts

   The client signs in with the details they use for that tax service, or creates them from the link.

4. Watch the expiry

   The link expires after 21 days. After that the process starts again. The account lists every request sent in the last 30 days with its status (GOV.UK).

Online agent authorisation

1. Request a code

   Sign in to HMRC online services for agents and choose "Authorise client" (GOV.UK).

2. The client receives a letter

   HMRC posts an authorisation code to the client within 7 working days.

3. Enter the code

   The client gives the code to the practice within 30 days of receiving it, and the practice enters it in its online services account. The code expires after that.

When form 64-8 is still used

Form 64-8 authorises an agent where online services are not available. GOV.UK lists Self Assessment, individual PAYE, VAT, the Construction Industry Scheme, Corporation Tax and tax credits. It cannot be used for Making Tax Digital for Income Tax or trusts. It is posted to HMRC at the address on the form and cannot be sent online. Since an update on 24 July 2026 GOV.UK states that the client must sign and date the form, and the agent codes for each tax must be correct.

A 64-8 does not give access to the Income Record Viewer (HMRC handbook). The Income Record Viewer uses the digital handshake, and that authorisation only allows viewing income data. It does not authorise the agent to speak to HMRC for the client (GOV.UK).

Authorising from the client's business tax account

A client can also authorise an agent from their own business tax account for the Construction Industry Scheme, Gambling Tax, Machine Games Duty, the Notification of Vehicle Arrivals, PAYE, VAT (legacy) and VAT MOSS (GOV.UK). For an employer client this is an alternative to a paper 64-8 for PAYE.

A new limited company client

For example, a new client that is a VAT-registered limited company with a payroll needs three authorisations: VAT by the digital handshake, Corporation Tax by online agent authorisation or a 64-8, and PAYE by a 64-8 or from the client's business tax account (GOV.UK). Each director who needs a Self Assessment return authorises the practice separately. Start all of them when the engagement letter is signed, because the online agent authorisation code is posted and the handshake link lasts 21 days.

Main and supporting agents for Income Tax

Making Tax Digital for Income Tax has main and supporting agent roles, authorised through the digital handshake. Copying existing Self Assessment authorisations into the agent services account makes the practice the main agent (GOV.UK). The roles are explained in agent roles for MTD for Income Tax.

Questions