From September 2026, HMRC stops waiting for sole traders and landlords above the first Making Tax Digital (MTD) for Income Tax threshold to opt in. If qualifying income from self-employment and/or property exceeded £50,000 in 2024/25 and you have not signed up for 2026/27, HMRC will enrol you in stages and tell you afterwards — digital message or post.
That is forced onboarding onto a live quarterly regime. Auto sign-up does not create digital records, authorise software, clean income sources, or file overdue quarterly updates. It only puts you on HMRC’s MTD map using data HMRC already holds — often stale.
For CFOs the risk sits with owner-managers and founders who still have property or trading income, portfolio directors with side lettings or consultancy, and agent relationships that still treat Self Assessment as a January event. Leave auto enrolment alone and you inherit messy source lists, missing software links, and a year-end scramble that still carries return and payment penalties even while quarterly points are soft for 2026/27.
What HMRC is actually doing this month
From 6 April 2026, sole traders and landlords with qualifying income over £50,000 in 2024/25 must use MTD for Income Tax for 2026/27. Qualifying income is turnover before expenses from self-employment and property. From September 2026, if you are in that cohort and have not signed up yourself or through an agent, HMRC will sign you up.
Core pages:
- Check what to do if HMRC has signed you up (updated 11 September 2026)
- Sign up for Making Tax Digital for Income Tax
- Find out if and when you need to use MTD
- MTD for Income Tax collection
The 11 September update matters. HMRC will also check records against the 2025/26 return if already filed. Ceased-income rules are tighter: stop everything before 6 April 2026 and you must still update the online account so you are not treated as live MTD; cease on or after that date and you still need MTD through cessation and the 2026/27 return.
Enrolment is staged. Silence is not out-of-scope. Check the online account; agents check the Agent Services Account (ASA) client by client.
Auto sign-up is enrolment, not readiness
HMRC’s “after we’ve signed you up” sequence is the control framework.
1. Right portal — individuals use HMRC online services with Self Assessment credentials; agents use the ASA, not legacy screens alone.
2. Live income sources — HMRC presents self-employment and property sources from prior returns. UK properties = one UK property business; foreign properties = one foreign property business. Add new sources; mark ceased ones. Do not rubber-stamp a 2024/25 snapshot if the founder sold a let in March or started a second trade in May.
3. Compatible software — HMRC does not supply it. Use the software finder, then authorise so records and quarterly updates can flow. Bridging only counts if the digital links are real; copy-paste is not MTD.
4. Catch up from 6 April 2026 — the first 2026/27 quarterly deadline was 7 August. Empty books in September still need day-one records and updates before the return can finalise. See Use MTD for Income Tax.
5. Annual calendar still lives — MTD does not abolish 31 January. Quarterly updates are income/expense summaries, not the tax return.
Also lock agent authorisation and the agent toolkit.
The penalty map CFOs keep getting wrong
Two clocks run at once.
For 2026/27 quarterly updates, HMRC will not apply penalty points for missed quarterly deadlines in this cohort’s first mandated year. Relief, not a holiday. You still need the digital trail and the final quarterly update before the tax return. Points still apply for missing the return deadline.
Once inside MTD, late submission and late payment move onto the new design: points-based late submission and more graduated late payment charges from the tax year you join. The prior-year return can still sit on old Self Assessment rules — so the 2025/26 return due 31 January 2027 often remains on the old clock. Late payment interest runs throughout.
Detail:
“No quarterly points in year one” is not permission to ignore software until spring. It softens one failure mode while HMRC hard-wires the rest.
Threshold glidepath — beyond the £50k cohort
Next waves are already published: over £30,000 qualifying income in 2025/26 → MTD from 6 April 2027; over £20,000 in 2026/27 → from 6 April 2028. Partnerships come later. Map LLP members and “small” founder vehicles now, or auto sign-up becomes next year’s surprise too.
See eligibility, qualifying income, and exemptions. Digitally excluded and other exemption routes exist. They are narrow. Disliking the software shortlist is not a group exemption strategy.
Why this hits PE, OMBs and portfolio CFOs
MTD for Income Tax is personal, but the operational load lands on business finance.
Founders and chairs often still hold property portfolios or advisory income. Auto sign-up hits the individual first, then the PA, then the CFO when the agent says the books were never digital from April. Earn-out monitoring rarely asks whether the individual’s Self Assessment side is MTD-ready; if property turnover clears the threshold, quarterly updates start regardless of the corporate close calendar.
Agent design matters. Main versus supporting agent permissions, ASA authorisations, and software links are now control items. If a bookkeeper owns property records and a tax firm owns the return, the engagement letter must say who files each quarterly update. HMRC’s agent toolkit is written for practices; CFOs should still demand that split in writing.
Data quality is the quiet failure. Auto enrolment uses HMRC’s stored sources. Wrong trade descriptions, dead properties, and missing overseas lettings create false quarterly baselines. Clean the source list in the month the letter arrives — not in January. And do not assume VAT MTD software covers Income Tax MTD for every individual; check the Income Tax list and the accounting-period setting separately.
What to lock this week
1. Population list — every director and key manager on Self Assessment with property or self-employment; flag 2024/25 qualifying turnover plausibly over £50k.
2. Status check — confirm in HMRC online services or the ASA whether MTD already shows as signed up; file evidence in the tax risk pack.
3. Income-source reconcile — active trades, UK and foreign property businesses, ceased dates, new starts; use the 2025/26 return where already filed.
4. Software owner — one authorised product path per person, named internal owner and agent owner, with a date.
5. April backfill — digital records from 6 April 2026 and any overdue quarterly update as soon as the link works; do not wait for 7 November to discover a dead bank feed.
6. Board wording — no quarterly points for missed 2026/27 updates; return and payment penalties still live; interest still live; 2025/26 return may still sit on the old clock.
7. Next waves — run the same list at £30k / £20k so April 2027 is not another surprise.
8. Exemptions only with evidence — digitally excluded or other exemption categories are narrow; hope is not an exemption.
Voluntary sign-up still beats being enrolled
If you or your agent sign up, you control the opening data. If HMRC signs you up, it uses what it already holds. That is why waiting for the letter is poor governance. Where someone is not yet enrolled, put them on the service with clean sources rather than inheriting a partial HMRC sketch.
Routes remain open via the individual sign-up service, agent client sign-up, and the step-by-step collections for businesses and agents.
Bottom line
September’s auto sign-up wave ends the fiction that MTD for Income Tax was still a future project for the £50k cohort. Enrolment is automatic. Compliance is not. Get every relevant individual onto the right sources, software link, April digital records, and a named quarterly owner — before the letter becomes an orphan process between the individual, the agent, and the year-end return.
Audit committee line: auto sign-up puts you on the register; it does not close the books.