Mark These in Your Calendar Now
- 📅 6 April 2026: MTD officially starts — you must be registered
- 📅 7 August 2026: First quarterly update due (April–June)
- 📅 7 November 2026: Second quarterly update due (July–September)
- 📅 7 February 2027: Third quarterly update due (October–December)
- 📅 7 May 2027: Fourth quarterly update due (January–March)
- 📅 31 January 2028: End of year declaration + tax payment due
What Does "Quarterly Update" Actually Mean?
It's not a full tax return. You're just telling HMRC a summary of what you earned and spent in those three months. Your software does most of the work. If your records are tidy, it takes about 30 minutes.
What Happens If You Miss a Deadline?
HMRC uses a points-based system. Each missed deadline earns a penalty point. Once you hit 4 points, you get a £200 fine. After that, each further miss is another £200.
The good news: one missed deadline won't immediately hurt you. But don't make a habit of it.