Gross income test, your start date, your four filing dates, and what one late payment costs.
Qualifying income (gross, annualised)
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Verdict on this return
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Mandated from
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First quarterly update due
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All four quarterly dates
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Final declaration due
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Late payment penalty modelled
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How that penalty was built
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Keep these dates instead of re-typing them Full version: exports each taxpayer's dated schedule and penalty working as a .csv you keep, and sets browser reminders fourteen days before every filing date. $60 once · one licence key per person or team seat · 7-day full refund. HMRC charges 3% of the tax still unpaid at day 15 and another 3% at day 30 — £480 on an £8,000 balancing payment. Get the full version — $60
The gross test, annualised Adds gross self-employment turnover to gross rents — receipts, not profit, and before expenses — then scales a part-year business up to twelve months the way HMRC's qualifying income test does.
Which 6 April pulls you in Maps the tax year on the return being tested to its own threshold and start date: 2024-25 return / over £50,000 / 6 April 2026; 2025-26 / £30,000 / 2027; 2026-27 / £20,000 / 2028.
Your four filing dates, printed Gives the 7 August, 7 November, 7 February and 7 May quarterly update deadlines for your first mandated year, plus the final declaration date that replaces the return.
What missing the date costs Applies 3% of the tax unpaid at day 15 and a further 3% at day 30, then 10% a year charged daily, with the first-year 15-day easement as a switch you can turn off.
Export the dated schedule (.csv) Paid layer: writes the start date, the four quarterly dates, the final declaration date and the penalty working to a .csv you keep — one per client, ready to paste into a practice tracker.
Reminders before each 7th Paid layer: sets browser alarms fourteen days before each filing date so the deadline finds you, instead of you remembering to open a checker four times a year.
Get the complete version $60
This page is the working piece. The full pack has everything below.
Gross income test, your start date, your four filing dates, and what one late payment costs.
HMRC charges 3% of the tax still unpaid at day 15 and another 3% at day 30 — £480 on an £8,000 balancing payment.
It adds your gross self-employment turnover to your gross rents, annualises them if the business ran less than twelve months, and compares that to the threshold for the return being tested. It then prints the 6 April you are mandated from, all four quarterly update dates, the final declaration date, and what a late balancing payment would cost.
Who is it for?
UK sole traders and landlords who file their own Self Assessment, and the bookkeepers and small practices who file for ten or fifty of them. If you have ever had to answer "does MTD start for this client in April 2026 or April 2027" from a folder of returns, this is the thing that answers it in seconds.
Why not just ask a chatbot or read a blog post?
Because the dates moved twice and most sources have not caught up. Chatbots still quote the abandoned April 2024 start, and many articles test profit rather than gross receipts, which flips the answer for anyone with high turnover and thin margins. HMRC's own checker wants a Government Gateway login and gives you no dates to keep.
What is free and what needs the key?
Every calculation is free and unlimited: the gross income test, the start date, the four quarterly dates, the final declaration date and the penalty model, for as many taxpayers as you like, with no key and nothing hidden. The $60 key adds exporting each schedule as a .csv you keep and browser reminders fourteen days before each date.
What would this cost me if I got it wrong instead?
HMRC charges 3% of the tax still unpaid at day 15 and a further 3% at day 30, then 10% a year charged daily. On an £8,000 balancing payment that is £480 before the daily charge starts. One missed date costs more than sixteen copies of the paid key.
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Free in the browser. The full version is a one-time licence, 7-day refund.