MTD for ITSA: Segmenting Your Client Book by Qualifying Income

Making Tax Digital for Income Tax is rolling in by income band, not all at once. Before you can plan software, fees, or engagement letters, you need to know which clients fall into each segment. This guide walks through the triage process: how to place each client, what to do for each segment now, and the conversations about records and software you should be having this summer.

The four segments

HMRC determines mandation by qualifying income — gross income from self-employment and property before expenses, combined across all sources. Partnership profit shares do not count. HMRC reviews the most recent return it holds and writes to affected taxpayers; you should not wait for that letter. The mandation bands are:

Sources: GOV.UK — Check if you're eligible for Making Tax Digital for Income Tax (thresholds verified June 2026); GOV.UK — Send quarterly updates.

Segment 1: mandated from April 2026 (over £50k)

These clients are already in MTD. If you haven't onboarded them onto compatible software and filed the first quarterly update by 7 August 2026, you are behind. The 2026/27 year carries no penalty points for late quarterly updates — HMRC has confirmed "there are no penalties for missing a quarterly update deadline for the 2026 to 2027 tax year" — but the obligation to file, and to keep digital records from 6 April 2026, is live regardless.

For this segment, the immediate actions are:

• Confirm each client is in MTD-compatible software and has granted your agent authorisation in the HMRC agent services account.
• Set the update-period election — standard (periods ending 5 July, 5 October, 5 January, 5 April) or calendar (periods ending 30 June, 30 September, 31 December, 31 March). The deadlines are identical either way. This decision cannot be changed after the first update is filed.
• Confirm digital records are running from 6 April 2026 — not reconstructed from bank statements in July.
• Diary all four quarterly deadlines: 7 August 2026, 7 November 2026, 7 February 2027, 7 May 2027.

The soft landing in year one is breathing room to iron out process issues. Use it deliberately — file a clean Q1 in August so any software, authorisation, or categorisation problems surface before penalty points are in play from 2027/28.

Segment 2: mandated from April 2027 (£30k–£50k on 2025–26 return)

This is the largest cohort by headcount at most practices. These clients are not yet mandated, but the qualifying income test will be applied to their 2025/26 returns — which you will be preparing through the autumn and winter of 2026. As you complete each return, record whether the client crosses £30,000 and flag them for Cohort 2 onboarding before April 2027.

The work to do now is identification and pricing, not onboarding. Pull any clients whose 2024/25 income was in the £25k–£50k range: those on the boundary need the most careful watch, because a single good year could move them into the 2027 cohort.

The 2027/28 year will carry the full points-based penalty regime — one point per missed quarterly update, £200 fixed penalty at four points, with further £200 penalties for subsequent failures. So the first year without a soft landing is this cohort's first year. Engagement-letter updates and software onboarding need to happen in early 2027, not at the last minute.

Segment 3: mandated from April 2028 (£20k–£30k on 2026–27 return)

The qualifying income for this cohort will not even be finalised until self-assessment returns for 2026/27 are filed — mostly in autumn and winter 2027. This segment requires monitoring, not action now. Keep a note against each client in the £20k–£30k band, and revisit when you complete their 2026/27 returns.

One nuance: income levels change. A client at £19,000 in 2025/26 who takes on extra work in 2026/27 could breach £20,000 and join this cohort. Track the boundary clients actively rather than assuming income is static.

Segment 4: out of scope (£20k or under, or exempt)

Clients below £20,000 qualifying income are not mandated. Do not migrate them early. There is no benefit to MTD for clients not required to use it, and the overhead is real — compatible software, quarterly filings, digital records from day one. The standard annual self-assessment return remains correct for this group.

Exempt categories — those without a National Insurance number, for example, or those already in certain benefits assessments — are similarly out of scope. Check the HMRC eligibility guidance for the full list before applying any exemption.

The borderline client: how to handle qualifying income uncertainty

The qualifying income test is based on the most recent return HMRC has on file. If a client's 2024/25 return has not yet been filed (for example, a late filer or one using a non-January filing cycle), HMRC will use the most recent available. For a client whose income has been volatile — say, £52k in 2023/24 and expected £42k in 2024/25 — the safe approach is to assume mandation applies until the 2024/25 return is filed and accepted. Do not advise a client to skip onboarding because you expect them to fall below threshold; wait until the return is filed.

Joint property is another borderline trap. Each owner tests their own share of gross rental income, not the combined total. A married couple with £60,000 in gross rent split equally are each at £30,000, which is below the 2026 threshold but in scope from 2027.

Record-keeping and software conversations to have now

For mandated clients, the practical conversations are about digital records, not software features. MTD requires income and expenses to be recorded digitally from the start of the tax year. The specific software is secondary to whether the client will actually use it.

Some practical questions to run through with each mandated client:

• Are they on a cloud bookkeeping tool already, or starting fresh? If fresh, what devices will they actually use? A phone-based tool is more likely to be used than a desktop application for a client who doesn't have a regular desk.
• Do they have multiple income sources — sole trade plus a rental property, for example? Each source needs to be captured separately, and the election of standard versus calendar periods applies per source.
• What is the handoff point to your firm? Establish a date by which records must reach you before each quarterly submission — well in advance of the 7th of the relevant month. Two to three weeks is realistic.
• If they use a spreadsheet and want to continue doing so, bridging software is a compliant option. It is not a reason to delay having the conversation.

The election decision: which quarter periods to use

Once you have identified a client as mandated, the period election is one of the first setup decisions. Standard periods end on the 5th (5 July, 5 October, 5 January, 5 April); calendar periods end on the last day of the month (30 June, 30 September, 31 December, 31 March). The filing deadlines — 7 August, 7 November, 7 February, 7 May — are the same regardless of which you choose. For most clients whose bookkeeping is done to month-end, calendar periods are simpler because the figures align with month-end bank feeds and reconciliations.

Tracking quarterly deadlines across a mixed practice

Once a practice has clients across multiple MTD segments — some in from 2026, more from 2027 — the compliance calendar changes shape. Where you previously had a single January peak for most self-assessment clients, you now have four deadlines per year per mandated client. A 50-client book with 20 mandated from 2026 means 80 quarterly submissions a year on top of the usual SA calendar.

PenaltyProof's MTD monitoring (paid plans, opt-in per practice) tracks all four quarterly deadlines — 7 August, 7 November, 7 February and 7 May — alongside the practice's Companies House, Corporation Tax, VAT, CIS, and payroll deadlines. The feature requires the MTD ITSA monitoring toggle to be enabled at /manage; once on, the practice receives advance alerts at 30, 14, and 7 days before each quarterly deadline. Alerts are at practice level, not per-client HMRC integration — PenaltyProof does not connect to HMRC agent services or hold client income figures.

FAQ

Does MTD apply to partnerships?

Not yet. Partnerships are not currently in scope for MTD for Income Tax. The government has indicated a future date but nothing is legislated. Individual partners who also have sole-trade or property income test their own qualifying income excluding partnership profit shares.

Does it apply to limited companies?

No. MTD for Income Tax covers self-employed individuals and landlords only. Limited companies have their own obligations — Corporation Tax, VAT, PAYE — none of which are part of MTD for Income Tax.

What if a client's income drops below the threshold in a later year?

HMRC has published guidance on ceasing MTD obligations. Clients can stop using MTD if they are no longer eligible, but must follow the correct process to notify HMRC. Do not simply stop filing quarterly updates without confirming the exit route.

My client is a landlord with no self-employment income. Are they in scope?

Yes, if their gross rental income exceeds the threshold. MTD for Income Tax covers both self-employment and property income. Gross rent before expenses counts, not the net profit.

This is general information, not advice — check the GOV.UK guidance, or a client's specific position with a qualified accountant, before acting. See also the MTD ITSA complete guide and 2026 rollout plan. Deadline reference: MTD ITSA quarterly update deadline.

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Sources
GOV.UK — Check if you're eligible for Making Tax Digital for Income Tax: https://www.gov.uk/guidance/check-if-youre-eligible-for-making-tax-digital-for-income-tax
GOV.UK — Send quarterly updates: https://www.gov.uk/guidance/use-making-tax-digital-for-income-tax/send-quarterly-updates
GOV.UK — Penalties for Making Tax Digital for Income Tax: https://www.gov.uk/guidance/penalties-for-making-tax-digital-for-income-tax