Self Assessment & MTD for Income Tax
For sole traders and landlords: quarterly updates and the final declaration under Making Tax Digital for Income Tax.
Coming soon
This module isn't live yet. Payroll, Bookkeeping and Point of Sale are available now — this guide is here so you can see what's coming.
What MTD for Income Tax is
Making Tax Digital for Income Tax Self Assessment (MTD ITSA) changes how sole traders and landlords report income. Instead of one annual return typed into HMRC, you keep digital records and send quarterly updates through software, then a final declaration that replaces the old tax return.
Who and when
MTD ITSA is being phased in by income level. Check your start date against HMRC’s current thresholds — Valix supports the digital record-keeping and submissions either way.
Quarterly updates
Each quarter you send HMRC a summary of your business and property income and expenses for the period. These build up a cumulative picture across the tax year — they are not final figures, so a later correction simply flows through.
- 1Keep your income and expenses up to date through the quarter.
- 2Open the quarterly update — Valix totals your income and expense categories.
- 3Review the figures and submit to HMRC.
The final declaration
After the tax year you finalise your figures, add any other income and reliefs, and make the final declaration (also called crystallisation). This confirms your income tax position for the year and replaces the old Self Assessment return.
Frequently asked questions
Do quarterly updates have to be perfect?
No — they are running summaries. You finalise everything at the final declaration, and adjustments carry through cumulatively.
Does this replace my tax return?
For income within MTD ITSA, the final declaration replaces the equivalent Self Assessment return.
Related guides
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