MTDLite — QuickStart Guide

Welcome to MTDLite — the simplest way to file your Making Tax Digital Income Tax quarterly updates. No accountant, no spreadsheet, no subscription trap.

What MTDLite actually does

MTDLite files your MTD Income Tax Self Assessment quarterly updates directly with HMRC — the four-times-a-year data submissions required if you're a sole trader or landlord above the MTD threshold. It is not MTD for VAT, and it doesn't handle your year-end Final Declaration (your accountant, or HMRC's own free channel, handles that in January).

MTDLite doesn't check, advise on, or correct your figures — it files exactly what you give it, in the format HMRC requires. You remain responsible for the accuracy of what you submit.

Getting started

  1. Sign up at mtdlite.co.uk — enter your email, no password needed. We'll email you a one-time sign-in link (valid 24 hours).
  2. Add a profile — this represents the person you're filing for (yourself, or someone else if you're managing filing on their behalf — a spouse, a client). Choose whether you use Standard or Calendar quarters (click the "?" next to this field if you're not sure which applies to you — it's usually Standard unless you've specifically elected Calendar quarters with HMRC).
  3. Add a National Insurance number to the profile — you'll see a warning on the dashboard if it's missing, and MTDLite won't let you file until it's set. This is separate from connecting to HMRC, so it's easy to miss on your first pass — do it right after adding the profile.
  4. Connect to HMRC — you'll be sent to HMRC's own sign-in page to authorise the connection using your own Government Gateway login. MTDLite never sees or stores your password.
  5. Sync your businesses — click Sync businesses on the profile card to pull in your self-employment and/or property businesses from HMRC. This isn't automatic — if a business you expect isn't listed, this is the button to press.
  6. Buy credits — £5 per filing. Buy in fixed bundles (2 credits/£10, 4 credits/£20) or enter a custom amount (2 credits minimum). You only need credits when you're ready to actually submit — everything above this step works without them.

Filing a quarter

  1. From your dashboard, click File quarterly update on the business that's due. MTDLite tries to pre-fill the period dates using HMRC's own record of what's currently open for that business, so the suggested dates are usually right — but double-check them.
  2. Enter your income and expense figures for the period — either itemised by category, or as one consolidated total. Not sure what a category means? The category glossary linked from the form gives HMRC's own official definitions, not our guesswork.
  3. Review the preview screen — this shows exactly what will be sent before you confirm.
  4. Submit. You'll see confirmation the moment HMRC accepts it, along with a downloadable PDF receipt.
  5. One credit is only used if HMRC accepts the filing — a rejected submission doesn't cost you anything, and you'll see HMRC's actual reason for the rejection, not a generic error. (One rejection worth knowing about in advance: if HMRC says the quarter can no longer be amended, it usually means your Final Declaration for that tax year has already been filed elsewhere — at that point HMRC won't accept further quarterly changes for it.)

Staying on top of your businesses

The dashboard shows a Due status for every business, pulled from HMRC's own obligation records, not a guess:

  • Up to date — next due date shown, nothing needed right now.
  • Due soon — a filing window is closing within the next 10 days.
  • Overdue — self-explanatory, and it tells you by how many days.
  • Unknown — HMRC hasn't returned obligation data for this business yet; this isn't necessarily a problem, it just means there's nothing to show.

Email reminders run on their own schedule, separate from the badges above: one the day a quarter closes, weekly after that, and a final one on the actual filing deadline. They stop the moment that business is filed — nothing more arrives once you're done, and each business is reminded independently, so if you've got more than one due at once, expect more than one email.

HMRC connections also expire periodically and need reconnecting — you'll see a Re-auth needed (expired) or Re-auth due soon (expiring shortly) badge on the profile when that's the case. Reconnecting is the same one-click Government Gateway flow as the original connection.

If you're ever unsure whether HMRC actually expects a filing from you at all (as opposed to just when one's due), the Check HMRC enrolment button runs a one-time enrolment/mandation check directly against HMRC — useful if something feels off and you want a straight answer from the source rather than MTDLite's own due-date logic.

Checking your history

  • Each business's Worksheet shows every quarter filed, with full detail and a downloadable PDF receipt for anything accepted.
  • The Annual Summary shows all quarters for a tax year together — cumulative figures, this-quarter-alone breakdowns, and a year-to-date estimate (this is a plain sum of what you've filed, not a tax calculation). Once a tax year's quarters are all in, a downloadable year-end summary PDF becomes available too.
  • If a quarter was ever corrected, you'll see an "Amended" badge with the full history available. Worth knowing: HMRC only ever keeps your most recent figures for a quarter on their side — MTDLite is what keeps the full amendment history for your own records.

Managing other people's filing (linked profiles)

If you're filing on someone else's behalf (a spouse, a client), add a profile with their email address instead of leaving it blank. They'll get a one-time secure link to authorise their own HMRC connection — they never need an MTDLite login or password of their own. If you leave the contact email blank, MTDLite assumes the profile is you and sends you straight to HMRC's sign-in instead.

Archiving a profile

Not currently acting for someone, or want a business tucked out of the way for a while? Click Archive on its profile card. It disappears from your default dashboard (find it again via View archived) and stops generating reminders — its filing history is completely unaffected either way.

Archiving deliberately disconnects the HMRC link. When you're ready to pick it back up, click Resurrect and reconnect through the normal HMRC sign-in flow — a clean start rather than trusting an old connection that's been sitting untouched, in case anything's changed while it was parked.

Your data

  • Download a full export of any profile's data at any time from your dashboard.
  • If you're a linked profile without your own MTDLite account, you can request your own data or ask to be removed by emailing [email protected].
  • Our accessibility statement, terms, privacy policy, and security disclosure process are all linked in the site footer if you need them.

Getting help

  • Quarter type confusion? Click the "?" next to it anywhere it appears.
  • Category names unfamiliar? See the category glossary linked from the filing form — sourced directly from HMRC's own official definitions.
  • Anything else — [email protected]
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