MTD glossary
You've been creating tax returns for years and are familiar with the process. Now with HMRC's Making Tax Digital (MTD) mandation, you've got new terms to use.
| Term | Definition |
|---|---|
| ASA |
A service offered by HMRC to allow tax agents to manage tax services online. You must register as a tax agent with HMRC before creating your ASA. |
| Calendar quarters |
An alternative to standard tax quarters that run from 6th April. Calendar quarters start on:
View MTD important dates. |
| Final declaration | The year-end submission for MTD. This replaces the annual SA100 (self-assessment) tax return. |
| MTD mandation | A requirement from HMRC that the self-employed and landlords with a total annual income of £50,000 (correct as of 6th April 2026), must must submit their Income Tax Self Assessment (ITSA) digitally under MTD. |
| MTD pilot | A chance before the 6th April 2026 launch date join the scheme and learn and test the new processes first. Find out more at https://makingtaxdigital.campaign.gov.uk/. |
| Quarterly obligations | The filing requirements expected by HMRC. These are submitted either based on calendar or tax quarters — view MTD important dates. |
| Tax quarters |
Standard tax quarters dictated by HMRC. Tax quarters start on:
View MTD important dates. |
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