How to identify your April 2027 MTD cohort before HMRC does

Making Tax Digital for Income Tax has been live since April 2026 for qualifying income over £50,000. The next wave, over £30,000, begins on 6 April 2027 — and HMRC will identify it from returns that are already in your practice.

4 min read · For UK accountancy firms

Here is the part that is easy to miss. HMRC works out who falls into that wave from 2025/26 self assessment returns. Those returns are in your practice now, either filed or about to be prepared. You can build the list before the letters arrive, and you can build it with more nuance than HMRC will.

That is an unusual position to be in. For once the profession can see a mandation wave coming with more than a year of notice and with the underlying figures already in hand. The question is whether firms use that lead time, or spend it on the January cycle and discover the cohort in February.

In scope is not the same as ready

Most firms already have a rough count of who is affected. A count is not a plan.

Working out who is in scope is arithmetic: qualifying income from self employment and property, above the threshold, in the relevant year. Most tax software will produce that list from last year's data in an afternoon.

Readiness is the harder half, and it is not a number your software holds. It is a judgement about whether a client can realistically keep digital records and submit something meaningful four times a year without your team doing it for them. In our conversations with practices, that second number is consistently smaller than firms expect — and the gap between the two lists is where the unbilled hours land.

A readiness split you can build in an afternoon

Segmenting by turnover or fee level tells you very little about the work involved. Segmenting by readiness tells you almost everything. Take the in-scope list and sort every client into one of four groups.

Needs Guidance is the group that decides your spring. It is usually the biggest, it is the one that absorbs capacity invisibly, and it is the only one where work done now reduces work done later.

Five questions that score readiness

If you want something more repeatable than instinct, score each client out of five. One point for each yes.

• Do they use cloud bookkeeping or accounting software today?
• Do records arrive without being chased more than once?
• Is their bank feed connected and reconciled at least monthly?
• Do they have one clear person responsible for the paperwork?
• Have they responded to a digital request from you in the last six months?

Four or five is Ready Now. Two or three is Needs Guidance and needs a plan. Zero or one means you are either changing how they work or absorbing the work yourself, and you should decide which on purpose rather than by default.

Three things worth doing before January

• Build the list from your own 2025/26 data rather than waiting for HMRC letters. The letters arrive in the middle of your busiest quarter, and they can be missed, ignored or sent to an old address.
• Have the fee conversation with every Needs Guidance client while it is a considered proposal, not an apology attached to a surprise invoice. Quarterly filing is a different service, not a slightly larger version of the old one.
• Fix the document habit before you pick the software. A client who does not send records on time annually will not send them on time quarterly. A fixed monthly rhythm, agreed in advance and requested the same way every time, does more than any tool.

There is a window between now and the end of November when the fee conversation is calm, informed and easy to have. After that, self assessment takes the diary.

Where the admin actually goes

The uncomfortable part of quarterly filing is not the submissions. It is the four rounds of chasing that precede them: requests sent by email, documents lost in a thread, three versions of the same file, and a team member spending their week on follow-ups instead of tax work. This is the operational half of MTD that we have written about before — and it is not a small cost.

That is the work to design out now, while there is still time to change the process rather than just absorb the volume. Standard document requests, automatic reminders and one place where clients upload, so that chasing stops being a person's job.

MyDocSafe gives practices that structure, with client onboarding, document requests and reminders running in the background rather than out of someone's inbox. But the tool is the second decision. The first is knowing exactly which clients need it.

Start with the list

Every mandation wave so far has rewarded the same thing: knowing your client base in detail before the deadline forces you to. Not better software, not earlier adoption, just a clear internal view of who can cope and who cannot.

The April 2027 cohort is already visible in the data you hold. The readiness split takes an afternoon in September and saves a quarter in the spring.

Thresholds per GOV.UK, “Find out if and when you need to use Making Tax Digital for Income Tax”: £50,000 from 6 April 2026, £30,000 from 6 April 2027, £20,000 from 6 April 2028. Checked 16 September 2026.