Update: HMRC-Led MTD Sign-Up Schedule (September 23rd 2026)

HMRC has officially begun its phased rollout for automatic MTD registration, starting with initial tests to validate system performance and support channels.

Key rollout timelines and expected volumes include:

• Phase 1: Controlled Start (September) – Small-scale testing with fewer than 10,000 customer records..

• Phase 2: Main Scale-Up (October – Mid-November) – Majority of the baseline rollout, up to 250,000 customers..

• Phase 3: Remaining Baseline (Mid-November – Mid-December) – Reaching the full 350,000 baseline target..

• Self Assessment Peak Pause (Mid-December – End of January) – Sign-ups will pause during the busy tax filing period..

• Contingency Capacity (February – End of March) – Additional migration capacity available post-baseline.

Note: These volumes represent current planning assumptions and may be adjusted as HMRC evaluates the early phases.