HMRC-led MTD sign up: advice for agents

Starting in September 2026, HMRC will begin to sign up those taxpayers who should have joined Making Tax Digital for Income Tax (MTD) in April 2026, but have not yet been signed up. 

In this short article, we set out some tips and advice for agents whose clients might be affected. 

What is HMRC-led sign up? 

Shortly after the first quarterly update deadline for 2026/27, HMRC issued a press release to confirm that 570,000 taxpayers (out of around 864,000 expected to be in scope) had successfully registered for MTD. To prompt those taxpayers who have not yet signed up to take action, HMRC announced that they will start signing them up from September 2026. 

It is only those taxpayers who were mandated into MTD for the 2026/27 tax year and have not already registered who will be signed up by HMRC at this time. Taxpayers who are required to join MTD from April 2027 or April 2028 are still expected to either sign themselves up in due course, or be signed up by their agent (unless they are exempt). 

Once signed up by HMRC, the taxpayer will receive a letter or digital message (depending on their contact preferences) advising them what this means and the next steps they need to take. This will include a specific ‘checking step’ which requires the taxpayer or their agent to confirm whether HMRC’s records are up to date. 

What is the checking step and what does it involve? 

The checking step is an additional action which needs to be undertaken where a taxpayer is signed up for MTD by HMRC. It is not required where the taxpayer has signed themselves up, or their agent has signed them up. 

The checking step can be carried out by the taxpayer via their Personal Tax Account/Business Tax Account, or by their agent through their Agent Services Account (ASA). 

The taxpayer / agent will be asked to check and confirm HMRC’s information on the active businesses they have. This is important, as HMRC's records are based on historic tax return data. This may mean that, for example, HMRC are expecting MTD filings for a business that it no longer being carried on. 

It will be possible as part of the checking step to notify HMRC where a business is no longer active, or where a new business has started. It will however not be possible to change the name attributed to a business (something which can only be done via the taxpayer or agent-led sign up process). The ability to change name may be useful to distinguish between multiple businesses which are currently listed under the taxpayer’s name alone. 

Where a business is ‘ceased’ under the checking step, HMRC will not expect ongoing MTD compliance. If instead a new business is added, this does not mean that it is within MTD straight away. Instead, under the ‘latency period’ rules, the new trade first has to be reported on a tax return. If the taxpayer wants to bring the a new business into MTD earlier they will need to do this via a separate step in the PTA/BTA or their agent can do so via the ASA. 

HMRC have provided us with example screenshots showing what the checking step will look like in the PTA/BTA/ASA. Please note these are illustrative examples only, and subject to change. 

How will agents know if a client has been signed up by HMRC? 

HMRC have advised that communications confirming sign up will be sent directly to the taxpayer, and that agents will not receive a copy. The letter/communications (a copy of which can be found in HMRC’s agent toolkit) will encourage taxpayers to discuss this letter with their tax accountant or agent. 

However, this raises the question of what happens if a client is signed up by HMRC and either does not receive the letter/communication, or does not pass it on to their agent? 

In the absence of any client list in the ASA, there is no way to quickly get an overview of whether any clients have been signed up by HMRC. The ATT have previously asked for a client list to be included in the ASA, and although HMRC have indicated they are looking into this, we do not have a timescale for when one might be available.

In the meantime, the only way to check is via the individual client’s records in the ASA. To do this, agents should log into their ASA, scroll to the Making Tax Digital for Income Tax section, click the link for “Manage Self Assessment details for clients that are already signed up” and input the UTR of the client they are checking. 

One of three things will then happen:

1. If the client has been signed up by HMRC, the agent will be presented with the “Manage your Self Assessment Module” screen. This is where the checking step described above is carried out. Once the checking step is complete, the agent will be taken to the client overview page instead.
2. If the client has already been signed up (either by themself or by the agent), the agent will be taken straight to the client overview screen.
3. If nobody has signed the client up, the client will not be found in the ASA. 

If a client is signed up by HMRC will they appear in the ASA? 

Yes – the position is no different whether sign up is carried out by the taxpayer, agent or HMRC. Provided the agent has authority to act, and any relevant online services account has been linked to the ASA then the client should appear in the ASA once signed up. 

What if a client is signed up by HMRC, but shouldn’t have been? 

HMRC-led sign up will be based primarily on the position shown in the 2024/25 tax return. This may not reflect any changes, such as cessations, which have occurred since that tax return was filed. 

The best advice to agents is to check, for those clients that you have concluded are not in MTD for 2026/27, whether HMRC may still be expecting them to sign up based on 2024/25 alone. Where this is the case, HMRC should be updated on the relevant change in circumstances via the Agent Dedicated Line (ADL). 

If a client is incorrectly signed up for MTD by HMRC, agents should contact them via the ADL as soon as possible to explain why they should not be in scope. 

What about exemptions? 

As set out in our dedicated guidance, a range of exemptions are available from MTD. Some of these apply automatically, and should be picked up by HMRC as part of their pre-sign up checks. Others which require an application to HMRC (such as on the grounds of digital exclusion, or where an SA109 is expected to be filed in 2025/26 or 2026/27 but was not in 2024/25) may not be picked up as easily. 

Where an exemption request has been submitted, but HMRC have not yet responded, it is worth asking those clients in particular to keep an eye out for any letters or other communications from HMRC. You may also want to periodically check the ASA from September onwards to see if they are signed up, following the steps above. 

Taxpayers who may qualify for an exemption, but have not yet applied, can still apply even after being signed up by HMRC. Where such an exemption request may be needed, the best advice is to submit it as soon as possible to avoid any uncertainty.