HMRC has updated its guidance for agents signing clients up to Making Tax Digital for Income Tax, adding a fresh reminder that the sign-up service will be unavailable during planned maintenance from 5pm on Friday 10 July 2026 until 9am on Monday 13 July 2026.
The guidance matters for accountancy practices, bookkeepers and the small firms that rely on them because the first mandatory MTD Income Tax year is already under way. HMRC says clients with total annual income from self-employment and property above £50,000 are required to use Making Tax Digital for Income Tax from 6 April 2026.
Agents who have eligible clients should treat the update as a prompt to check whether sign-up, software access and client authorisations are all in place before the July service window closes. A short outage is not a major policy change, but it can still create avoidable pressure if a practice is trying to move several clients across at the same time.
What HMRC is telling agents
The GOV.UK page says agents should sign up clients now if they are required to use MTD Income Tax for the 2026 to 2027 tax year. HMRC will check eligibility using the details provided during sign-up.
To sign up a client, the client must be registered for Self Assessment and must have submitted a tax return in the last two years. HMRC also says agents need the client’s permission before signing them up.
Existing Self Assessment authorisations are recognised for MTD Income Tax, but agents still need to make sure the correct authorisation route is in place. Practices that use an Agent Services Account should check that team members know which account and client records they are working from, especially where older HMRC online services accounts are still used for other tasks.
HMRC’s wider MTD Income Tax manual also reminds taxpayers and agents that the first year involves more than a one-off registration. Businesses need compatible software, digital records, quarterly updates, any required adjustments, and the final tax return process through software that works with the service.
Why small firms should care
For many small businesses, MTD Income Tax will be handled in practice by an accountant or bookkeeper. That does not mean the owner can ignore the change. A missed authorisation, unsuitable software choice or unclear record-keeping process can still land back with the business when quarterly updates are due.
Sole traders and landlords near or above the £50,000 threshold should ask their adviser whether they have been signed up, which software will be used, what records need to be kept digitally, and how often information will need to be shared. Firms below the 2026 threshold may still want to prepare, particularly if income is rising or if they expect to come into scope later.
There is also a practical cash-flow angle. Moving to quarterly digital updates does not by itself change when Income Tax is paid, but it can change the rhythm of admin through the year. Businesses that leave bookkeeping until January may need a more regular routine, even if their adviser does most of the filing.
Checks to make before the July maintenance window
Small firms using an adviser should confirm who is responsible for sign-up and whether HMRC’s eligibility checks have been completed. They should also check whether any old Self Assessment authorisations need tidying up, particularly if they have changed accountant in the last few years.
Practices should review which clients are already in scope, which clients may sign up voluntarily, and which clients may need an exemption check. HMRC tells agents to check whether a client may be exempt before signing them up.
Software should not be treated as a final-week task. HMRC’s guidance says agents and clients should make sure software works with MTD Income Tax and meets their needs. That means testing access, checking accounting periods, and making sure client records can support quarterly updates.
BritishSME has previously covered an MTD Income Tax service issue affecting refunds. The latest update is a different point, but the lesson is similar: firms should keep an eye on service availability and build enough slack into tax admin so a short HMRC outage does not become a deadline problem.
What to do now
If your business is likely to be in scope, ask your adviser for a clear MTD Income Tax status update. The useful answers are simple: whether you are required to join from April 2026, whether sign-up is complete, which software will be used, what information you need to provide each quarter, and who will monitor HMRC service availability.
For advisers, the immediate action is to avoid leaving sign-up batches around the planned July downtime. For small firms, the action is to make sure the move to digital records is visible inside the business rather than treated as something that happens entirely inside the accountant’s office.
Sources
Sources: HMRC guidance on signing up a client for MTD Income Tax; HMRC MTD Income Tax manual; HMRC MTD Income Tax service availability and issues.
