Quarterly income tax, drafted from your ledger , not your nerves.
Once your qualifying income passes £50,000, HMRC requires quarterly Making Tax Digital updates through software, with your tax return then completed in the same software — mandatory from 6 April 2026, dropping to £30,000 in 2027 and £20,000 in 2028 (gov.uk, read 12 October 2026). ac-co drafts each quarter's update from your live bank and books and keeps the cumulative position straight.
From connected to filed, in four moves.
Everything this plan files, keeps and tells you.
Drafts for you
Prepared from your bank and books for you to review. Live filing to HMRC is not open yet.
- Four quarterly updatesSelf-employment and property income, totalled by category and ready for you to check before anything is sent.
- The year-end tax returnDrafted from the same records once your fourth update is in. You still submit one tax return a year, by 31 January.
Keeps for you
The transactions behind each submission, cross-checked.
- The quarter's transactions behind each submission
- The cumulative position, cross-checked quarter on quarter
Tells you
The next deadline, and what the quarter means for your bill.
- The next deadline, before it arrives
- What the quarter implies for your year-end bill
Four updates a year, one way or another.
Everyone mandated for MTD ITSA sends the same four quarterly updates and then completes a tax return — the difference is who does the totalling.
| Row | Spreadsheet + bridging software | An accountant | ac-co |
|---|---|---|---|
| £/year | Cheap software, your own time | £150–£400 for a Self Assessment return [Sleek — accountant fees for Self Assessment, UK, 2026-09-13] | Quarterly updates £0 · included from £14/mo |
| Hours/year | Four deadlines you track yourself | Low — but you still gather the figures for them | Minutes a quarter — totals come from your bank and books |
| Cumulative position kept straight quarter to quarter | No | If they check it | Yes |
| Mandatory once qualifying income passes £50,000From 6 April 2026 — the threshold drops to £30,000 in April 2027 and £20,000 in April 2028. | From 6 April 2026 [gov.uk, Making Tax Digital for Income Tax thresholds, 2026-09-14] | From 6 April 2026 | From 6 April 2026 |
| Year-end tax return included | No | Yes | Drafted for you; live filing not open yet |
Accountant fee dated 2026-09-13 — check their own quote for an MTD ITSA service specifically.
Try the Income Tax calculator — no sign-up.
An estimate from the figures you enter — not a filed quarterly update. Your real position is drafted from your connected books and bank.
Ready when you are.
Am I actually mandated yet?
From 6 April 2026, anyone whose 2024/25 qualifying income (self-employment and property, before expenses) was over £50,000 must use MTD for Income Tax. The limit is £30,000 from April 2027 and £20,000 from April 2028. Check the HMRC eligibility tool if you're close to the line.
What if I miss a quarter?
HMRC applies no penalty points for late quarterly updates in 2026/27. From 2027/28 each missed update or tax return deadline is one point, and four points bring a £200 penalty. ac-co drafts the update from your connected bank and books and shows the next deadline before it arrives.
Does ac-co file my quarterly updates yet?
As of 12 October 2026, ac-co Income Tax (MTD) is in open beta and live filing of quarterly updates to HMRC is not open yet. Use software from HMRC's list for any real deadline that falls before it opens.
Does this replace my Self Assessment return?
No. You still submit one tax return a year, by 31 January, but from 2026/27 you complete it in your MTD software after your four quarterly updates. For the tax year before you join, you file a Self Assessment return as normal. Your other taxable income goes in the return too.
I have two businesses and a property.
Every trade and every property is totalled separately by HMRC category, then combined into one cumulative position — you see all of it in one place, not four spreadsheets.
Can my accountant see it?
Yes — invite them into the same workspace to review before a quarter is submitted, whether or not they use ac-co day to day.
Want a seat in the beta?
Leave your email and we'll open a seat on MTD for Income Tax for you in the next batch.