Quick answer
MTD for Income Tax keeps the Self Assessment system but changes how you report. Instead of one return a year, you keep digital records, send four quarterly updates from software, and submit a final declaration by 31 January. Your tax, allowances and payment dates stay the same.
Side by side
| Self Assessment | MTD for Income Tax |
|---|---|---|
Records | Any format, including paper | Digital, in compatible software |
During the year | Nothing to send | Four quarterly updates |
After the year | Tax return by 31 January | Final declaration by 31 January |
How you submit | HMRC online or software | Compatible software only |
Payments | 31 January and 31 July | No change |
What stays the same
How much tax you pay, and the allowances and reliefs you can claim
Payment dates and payments on account
The 31 January deadline for the year-end submission
What expenses are allowable
Your last Self Assessment return
You file the year before you join MTD the old way. For example, if you start MTD on 6 April 2026, your 2025/26 return is still a normal Self Assessment return, due by 31 January 2027.
Read more about quarterly updates and the final declaration.