9. Assumptions and Open Inputs
The idea arrived as a catalog row (D4) and a short description. Hours per week, location, team, contacts, stage and budget weren't supplied. Here's what was assumed, and how the verdict changes if each assumption is wrong.
9.1 Assumptions made
| Input | Assumption used | If actually different… |
|---|---|---|
| Hours per week | Two tracks: ~15 hrs/week and full-time | Under ~10 hrs/week, you can't sell in every buying window and support deadline spikes. Multiply the 15-hrs/week odds by ~0.6. |
| Location | Unknown. The plan assumes you can run a UK-facing business: UK hosting, GBP pricing, UK VAT handling, and support in UK hours | If you're outside the UK with no UK partner, trust and support in UK hours get harder. Multiply by ~0.8. |
| Access to UK accountants | None assumed | A practising UK accountant or bookkeeper with 30+ MTD clients as design partner is condition 1. With one, odds rise to the table's figures. Without, multiply by ~0.6. |
| Stage | Idea. No code, no users, no revenue | Any practice already paying for a manual version changes the picture. Send it. |
| Team | 1–2 people, technical, no accounting background | An ex-practice accountant or practice manager on the team is the single biggest positive change. |
| Budget | Bootstrapped, ~£300–600 a month in tools, messaging and Cyber Essentials in year 1 | More money doesn't change the plan. It buys ISO 27001 sooner, which matters only for larger firms. |
| Exchange rate | £1 = $1.33 (unverified; used only to convert the ladder) | A 10% move changes the practice count needed by ~10%. |
| Pricing | £39 / £89 / £179 a month by MTD client band, annual = 2 months free, blended ~£75 | If practices won't pay above £39, $10k needs ~250 practices, and the full-time $10k odds fall to ~9%. |
| Messaging costs | WhatsApp and SMS ~£0.02–0.05 a message in the UK (unverified) | If UK SMS is nearer £0.08, cap SMS harder and push WhatsApp and email. Margin stays ≥80% with caps. |
| MTD timetable | £30k from April 2027 and £20k from April 2028 go ahead as published (GOV.UK, updated 26 Mar 2026) | A delay removes the expansion engine and the Feb–Apr 2027 window. Multiply $5k+ odds by ~0.7. |
| Competitor terms | Content Snare's per-active-request pricing (verified) makes large quarterly batches costly; Glasscubes MTD Assist is free for firms (verified wording, terms unknown) | If recurring requests don't count as "active" in Content Snare, the pricing edge is smaller. Check with a trial account in week 1. |
9.2 Inputs that would change the verdict most (please supply)
- Hours per week available, and for how long.
- Where you're based, and whether you can run a UK company or UK VAT registration.
- Any UK accountant, bookkeeper or practice manager you know, especially one with MTD IT clients.
- Any experience in accounting or practice software. It changes how fast discovery goes.
- Budget and runway for 24 months.
- Why this idea. If the answer is "I want a document portal for many professions", the verdict is No. If it's "I want a narrow UK tool that runs four times a year", it's a Go at the odds shown.
9.3 Definitions used throughout
- MTD IT: Making Tax Digital for Income Tax. Quarterly updates for sole traders and landlords above the qualifying-income threshold.
- Quarterly deadlines: 7 Aug, 7 Nov, 7 Feb and 7 May, for cumulative periods from 6 April (standard) or 1 April (calendar).
- Practice: an accounting or bookkeeping firm that is the paying account, whatever its number of users.
- MTD client: one taxpayer the practice chases each quarter.
- Tier A and Tier B: as in the portfolio README.
- Churn: monthly logo churn of paying practices. Healthy for small-practice B2B software: ≤3% a month (a judgment benchmark, not verified).