Agent Authorisation Explained
If you use an accountant (agent) to handle your MTD submissions, they need your authorisation before they can act on your behalf. This page explains how authorisation works for both agents and individuals.
What is agent authorisation?
Agent authorisation is the process by which a taxpayer grants an accountant permission to submit MTD data to HMRC on their behalf. Once authorised, the agent can:
- View the client’s obligations and submission history
- Submit quarterly updates
Two types of agent
HMRC supports two agent roles for MTD:
| Agent type | What they can do |
|---|---|
| Main agent | Can send quarterly updates, submit the client’s tax return and view tax calculations |
| Supporting agent | Can send quarterly updates, but cannot submit the tax return or view tax calculations |
Most accountants act as main agents for their clients.
How the authorisation flow works in aligned.tax
If you are an accountant
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Set up an Agent Services Account - If you do not already have one, register at HMRC’s Agent Services Account portal. This is your central account for managing MTD clients.
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Add the client in aligned.tax - Enter their name, email, NINO and postcode, then choose Main agent or Supporting agent.
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Send an authorisation request - aligned.tax generates an HMRC authorisation link for the client.
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Client approves the request - Your client receives the link, signs in with the correct HMRC account details, and approves your request. The link expires after 21 days.
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Authorisation confirmed - Once approved, check the client status in aligned.tax before you submit on their behalf.
If you are filing for yourself
If you are a sole trader or landlord filing your own MTD submissions (without an accountant), you do not need agent authorisation. Instead:
- Sign in with your Government Gateway - Connect your HMRC account directly through aligned.tax.
- Authorise aligned.tax - Grant aligned.tax permission to submit data to HMRC on your behalf.
- You are ready to go - You can submit your own quarterly updates.
No agent is involved. You are acting for yourself.
How are existing Self Assessment authorisations added?
If you already hold Self Assessment authorisations in your HMRC online services account, you can add them to your Agent Services Account using the Self Assessment agent code linked to those clients.
Key points:
- Adding a Self Assessment agent code adds all client authorisations linked to that code
- Repeat the process for each Self Assessment agent code your practice uses
- Clients usually do not need to authorise you again when an existing relationship is added this way
- Added authorisations make you the main agent for those clients
- Adding an authorisation does not sign the client up for Making Tax Digital - you or the client must still use the MTD signup service
- Your HMRC online services account continues to work alongside the Agent Services Account
See GOV.UK’s guidance on adding client authorisations for the current steps.
If you are an accountant
Setting up your Agent Services Account:
- You need an Agent Services Account before you can act for any MTD clients
- Register through HMRC’s online portal if you do not already have one
- Your agent reference number (ARN) is linked to this account
Managing authorisations:
- Check which Self Assessment agent codes have already been added to your Agent Services Account
- Add any missing agent codes before signing up each eligible client for MTD
- For new clients, send the authorisation link early because it expires after 21 days
- Discuss the new penalty regime with clients before signing them up, as HMRC requires clients to agree to the new penalties
Agent types:
- Choose the authorisation type that matches the relationship you hold with the client
- Both authorisation types shown in aligned.tax can participate in quarterly updates
If you are filing for yourself
Connecting to HMRC:
- You need a Government Gateway account. If you do not have one, you can create one at gov.uk
- Sign in through aligned.tax to link your HMRC account
- You authorise aligned.tax directly - no agent is involved
Your Government Gateway:
- This is your HMRC identity, separate from your aligned.tax account
- Keep your Government Gateway credentials safe - you will need them to authorise software and manage your tax affairs
- If you forget your details, HMRC can help you recover access
FAQ
Do my existing SA clients need to re-authorise?
Usually not. Add the relevant Self Assessment agent code to your Agent Services Account so HMRC can add the existing authorisations linked to it. You must still sign up each eligible client for Making Tax Digital. New clients without an existing Self Assessment authorisation use the digital handshake.
What if my client cannot sign in to their HMRC account?
They need the correct sign-in details for the tax service they are authorising. They may have more than one account. Direct them to GOV.UK’s HMRC online services help if they cannot sign in.
How long does authorisation take?
The client must respond to a digital-handshake link within 21 days. After they approve it, check the authorisation status in aligned.tax before submitting on their behalf.
Can I revoke an agent’s authorisation?
Yes. Clients can revoke agent authorisation at any time through their HMRC online account. Agents can also remove clients from their Agent Services Account.
What is the difference between 64-8 and MTD authorisation?
The 64-8 is the traditional form for authorising an agent for Self Assessment. An agent can add existing Self Assessment authorisations to their Agent Services Account using the relevant agent code. A new client relationship for MTD normally uses a digital-handshake link, which expires after 21 days.