Making Tax Digital for Income Tax Self Assessment (MTD ITSA) enters its first mandatory phase in April 2026. After years of delays, the rollout is now fixed — and accountants managing self-employed clients and landlords need to be ready.
Who enters scope first
From April 2026, MTD ITSA applies to individuals with qualifying income above £50,000 from self-employment or property. This is estimated to bring over 780,000 taxpayers into scope in the first wave.
The threshold drops to £30,000 from April 2027, and a further threshold of £20,000 is under consideration for a later date.
What the new obligations look like
Under MTD ITSA, each in-scope client must:
- Use MTD-compatible software to keep digital records
- Submit quarterly updates to HMRC — four per year, due within one month of each quarter end
- Submit a final declaration (replacing the Self Assessment tax return) by 31 January
That's five submissions per client per year — four quarterly updates plus the final declaration. For a practice with 100 in-scope clients, that's 500 submissions annually.
The quarterly submission deadlines
For a standard April–March tax year, quarterly deadlines fall on:
- 5 August (quarter ending 5 July)
- 5 November (quarter ending 5 October)
- 5 February (quarter ending 5 January)
- 5 May (quarter ending 5 April)
Clients with non-standard accounting periods may have different quarter-end dates. HMRC allows calendar-quarter alignment for simplicity.
Prep checklist for agents
- Identify all clients with qualifying income above £50,000 — check both self-employment and property income combined
- Ensure they have or will have MTD-compatible software by April 2026
- Review your own systems for tracking five-times-as-many submission deadlines
- Consider whether your current fee structure covers the additional work
- Sign up for HMRC's agent services account if not already done
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