MTD multiplies the work.
Calceum is built to absorb it.
From April 2026, MTD for Income Tax puts your sole trader and landlord clients on quarterly digital filing: four quarterly updates for each income source, then a final declaration, every year, for every affected client. Calceum is built to run that cycle inside the platform your practice already works in, on HMRC's official MTD APIs, and included for every practice on Calceum, to use if you choose. We expect HMRC production access by the end of October 2026.
The maths is the problem.
MTD doesn't make tax harder. It makes it more frequent, and frequency is a capacity problem. Staffing for it is one answer. Absorbing it into the platform is the other.
Submissions per affected client, per year
Four quarterly updates for each income source, plus the final declaration.
Submissions a year for a practice with 100 affected clients
Due by 7 August, 7 November, 7 February and 7 May, then 31 January for the final declaration.
Waves of clients between April 2026 and April 2028
Each threshold drop pulls more of your list in.
Three waves. Each pulls in more of your client list.
Qualifying income is self-employment and property income combined, measured from the previous tax year. The thresholds only move one way.
Sole traders and landlords with qualifying income over £50,000. The first wave, and for most practices, the largest.
Clients with qualifying income between £30,000 and £50,000 join the quarterly cycle.
The planned £20,000 threshold brings in the long tail of smaller clients.
How the quarterly cycle runs in Calceum.
Records flow in
Clients keep digital records in the app, or stay in the spreadsheets they already use with digital links into Calceum. Chasing missing records is handled by the platform, not your inbox.
Calceum prepares the quarter
Income and expenses roll up into the figures HMRC expects, with digital links maintained from record to return, with no copying, no re-keying.
Your team reviews and submits
One screen to review and submit through HMRC’s official MTD APIs, with a full submission log and deadlines tracked across every client on the platform. Submission opens once our HMRC production access is granted.
Included with Calceum.
Not sold separately.
Calceum isn't consumer software, and MTD isn't an add-on. It's part of the platform, included in your monthly retainer, with no per-client fees, no separate tool for clients to buy, nothing to resell. Using it is optional: keep your current MTD software if you prefer.
- Built on HMRC’s MTD APIs
- Self-employment, UK & foreign property
- No per-client fees
- Your brand in front of your clients
Calceum is available through accounting practices, not directly to individuals. If you want your MTD handled this way, ask your accountant about Calceum, or introduce us.
hello@calceum.comMTD,
answered.
What practice owners ask us about MTD for Income Tax. Something else on your mind? Book a 30-minute discovery call.
Sole traders and landlords, based on qualifying income: self-employment and property income combined, from the previous tax year. Over £50,000 from April 2026, over £30,000 from April 2027, and over £20,000 from April 2028 (planned). Calceum helps you map which clients fall into each wave.
Four quarterly updates for each income source (self-employment, and each property business), due by 7 August, 7 November, 7 February and 7 May. Each update is a running total of income and expenses, so corrections can be made in a later update. Then the final declaration, the year-end tax return, by 31 January. Calceum is built to prepare each update from the client’s records and track every deadline.
Not yet. We are completing HMRC production recognition for MTD for Income Tax and expect production access by the end of October 2026. We won’t claim recognition until it is granted. Calceum is built on HMRC’s official MTD APIs, and digital links are maintained from the client’s records through to the return, with no copying or re-keying, which is what HMRC requires.
No. Using Calceum for MTD is optional. It’s there in your retainer if you want it, and if your practice already files MTD with other software, you can keep doing that and use Calceum for everything else.
It’s included in your monthly retainer, and using it is optional. There are no per-client MTD fees and nothing for your clients to buy. We’ll walk through practice pricing when we talk.
HMRC uses a points-based system: a point for each missed deadline, and a £200 penalty once a client reaches four points. For the 2026 to 2027 tax year, HMRC is not giving points for missed quarterly updates; they apply from 2027 to 2028. A missed tax return deadline still counts. With quarterly filing across a client base, deadline tracking has to be systematic, and Calceum is built to track every client’s deadlines in one view.
No. Calceum is only available through accounting practices. It isn’t sold to individuals. Your clients get a branded portal and a better experience; the platform, including MTD, belongs to your practice.
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