Last checked: 9 September 2026 · Source: GOV.UK
If your qualifying income is under the current threshold, you're not required to use MTD for Income Tax. But you can choose to sign up early, before it becomes mandatory for you, and plenty of people do exactly that.
Broadly, you need to be a UK resident with a National Insurance number, registered for Self Assessment, up to date with your tax affairs, and to have submitted at least one Self Assessment return already. HMRC checks eligibility when you apply, so this isn't guaranteed just because you'd like to try it.
You get familiar with quarterly filing and your chosen software before it's compulsory, instead of learning it under pressure alongside a hard deadline that already has penalties attached. You also get access to HMRC's dedicated MTD support team while you're testing the process, which isn't available to you in the same way once the requirement has fully landed.
This part is more nuanced than most summaries let on, and we'd rather flag the complexity plainly than oversimplify it into something misleading. Based on GOV.UK guidance for volunteers: there are no late submission penalties for missing quarterly update deadlines while you're volunteering. But if you later become mandated into MTD, because your income crosses a threshold, your penalty point threshold changes from 2 points to 4 points, and a period of on-time compliance may be required first before that shift settles.
Sole traders and landlords sign up through HMRC's online service. Agents have a separate route to sign up clients on their behalf. You'll need your Government Gateway login, the date your business or property income started, and, for sole traders, your business name, address and trade.
Volunteering isn't automatically the right call for everyone under the threshold. If your income is unlikely to grow past £20,000 any time soon and you're comfortable with your current Self Assessment routine, there's a reasonable case for simply waiting until a threshold actually reaches you, rather than taking on quarterly filing for a system you don't yet need.
Whether you volunteer early or wait for mandation, every date that follows is already in the calendar.