For owner-managed UK SMEs, the April 2026 MTD ITSA entry depends on business structure first and gross income second. Sole traders and partners in partnerships above £50,000 of combined self-employment and property income in 2024-25 are inside MTD from 6 April 2026. Limited companies are outside MTD ITSA entirely; they sit under the eventual MTD for Corporation Tax programme which has no fixed rollout date. Many small business owners are uncertain whether they are inside or out because the structure-income interaction is not obvious.
This piece walks the eligibility test, the structure-by-structure analysis, the partial-year scenarios common in startup and exit years, and the practical steps for the first quarterly submission. Sister pieces in the MTD owner-managed SME hub cover quarterly updates and the Final Declaration and the best MTD software choices.
Structure determines whether MTD applies
Why gross income, not profit
The £50,000 threshold is gross qualifying income, measured before any expenses or allowances are deducted. A sole trader with £55,000 of turnover and £30,000 of allowable expenses (giving £25,000 of taxable profit) is inside MTD because the test ignores expenses. This is the most common point of confusion when explaining MTD to owner-managed business clients; they expect "if I am not making much profit, MTD does not apply", and that is not how it works.
Combining sole trader and property
Where a sole trader also rents out a property personally, the two income sources combine for the threshold test. A consultant earning £35,000 of sole trader turnover and £20,000 of rental income is inside MTD at £55,000 combined. The combined entity then submits separate MTD updates per source (one for the trade, one for the property), but the threshold test is across both.
Partial-year scenarios
A sole trader who started trading mid-2024-25 has a partial year of income on the 2024-25 return. HMRC tests the 2024-25 figure as-is for April 2026 entry, without grossing-up to a full year. A trader with 5 months at £6,000 per month (£30,000) is outside MTD for April 2026 entry even though the annualised rate would be £72,000. The next-year test (2025-26 return filed January 2027) will catch the full year, putting the trader inside MTD from April 2027 at the £30,000 threshold.
The HMRC notification letter
HMRC writes individually to taxpayers it believes are inside MTD ITSA from April 2026, based on 2024-25 Self-Assessment data. Letters arrive between October 2025 and February 2026. Receiving the letter is the strongest signal. Not receiving it does not guarantee exemption, particularly for taxpayers who filed 2024-25 late or amended after HMRC's threshold sweep ran. The legal obligation to enter MTD is independent of receiving the letter.
The threshold reduction schedule
- April 2026: £50,000 (largest owner-managed sole trader cohort enters).
- April 2027: £30,000 (mid-portfolio landlords and small consultants brought in).
- April 2028 (expected): £20,000 (single-trade self-employed brought in).
- Partnerships: separate later timetable, currently expected April 2027 or later.
- Limited companies: MTD for Corporation Tax under consultation, no fixed rollout date.
Should I incorporate to avoid MTD ITSA?
Incorporating a sole trader business into a limited company moves it out of MTD ITSA and into the (still-future) MTD for Corporation Tax programme. This is a side benefit of incorporation rather than the primary reason; the main drivers are corporation tax rates vs personal tax marginal rates, salary-dividend extraction efficiency, and limited liability. For a sole trader profit around £50,000-£80,000, incorporation often makes tax sense anyway and MTD avoidance is a bonus. For lower-earning sole traders, the admin overhead of incorporation typically outweighs the saving.
Voluntary entry below threshold
A sole trader below £50,000 can voluntarily enter MTD ITSA from April 2026. The case for voluntary entry: business expected to cross threshold within 12-18 months, business already on cloud accounting and the operational change is small, business prefers the discipline of quarterly close. The case against: extra software and agent costs without immediate need. Most accountants advise voluntary entry only where threshold crossing is genuinely imminent.
Practical next steps
- Confirm 2024-25 gross qualifying income from the filed Self-Assessment.
- If above £50k, await the HMRC notification letter (October 2025 to February 2026).
- Migrate to MTD-compatible software by end-2025 if not already on cloud accounting.
- Set up the agent authorisation under the new MTD scheme (not the old 64-8).
- Reconcile opening position at 5 April 2026 to give clean first quarter.
- First quarterly update due 7 August 2026 (covering 6 April to 5 July).
What if my 2024-25 return is not yet filed?
File the 2024-25 return as early as possible in the year (May or June 2025 ideal). Late filing (after the HMRC threshold sweep in late February 2026) means HMRC may not identify you as inside MTD, the notification letter may not arrive, and you may inadvertently miss the first quarter. The legal obligation still applies, so the practical consequence is reactive catching up rather than planned entry. Early filing is the cheapest insurance.