9. Assumptions and Open Inputs
This idea came from row D2 of the 30 Sept 2026 micro-SaaS idea catalog, not from a founder's brief. No team, hours, geography, price, stage or traction were supplied. Here's what I assumed, and how the verdict changes if each assumption is wrong.
9.1 Assumptions made
| Input | Assumption used | If actually different… |
|---|---|---|
| Platform | Xero, chosen on evidence (01) | If you already have a QuickBooks audience or an Airtable following, that access can outweigh the crowding. Re-score. |
| Target customer | Bookkeeping practices with 10–250 Xero clients | Selling to single businesses: multiply odds at $5k+ by ~0.5 (churn). |
| Geography | UK or Australia first, one of the two | New Zealand alone is too small for $10k+. The US is QuickBooks territory. |
| Pricing | $49 / $129 / $249 per practice per month, ~$90 blended | If practices won't pay above $49, customers needed roughly double at every rung. |
| Hours | Two columns: ~15 hrs/week and full-time | Below ~10 hrs/week, support response times suffer and the listing sinks. Use the "as described" column. |
| Stage | Idea. No code, no users, no revenue | Any paying practices change the picture more than anything here. |
| Team | One developer, with or without bookkeeping experience | Bookkeeping experience is condition 1. Without it, multiply by ~0.65. |
| Churn | 4–5% monthly for practices after month 6 | At Data Fetcher's 10% gross, the $10k rung roughly halves and $20k is out of reach. |
| Store share of acquisition | 40–60% of trials from the Xero App Store and organic search | Data Fetcher's 70–80% was Airtable. No Xero figure was found. |
| Xero pricing | Stays as announced for 2026 | Another change, up or down, moves margin, not the verdict. A ban on bulk-write apps would end it. |
| FX | ~US$0.65 per AUD, ~US$1.30 per GBP | Rounding only. |
9.2 Inputs that would change the verdict most (please supply)
- Bookkeeping background. Have you done Xero cleanups yourself, and how many?
- Hours per week available, and for how long you can hold that cadence.
- Practice access: how many Xero bookkeepers or firms you can reach in 3 weeks, and in which country.
- Build skill: have you shipped an app on an accounting API (Xero, QuickBooks) with OAuth and a job queue?
- Any existing audience on Airtable, QuickBooks or Xero (a newsletter, YouTube, a community role).
- Budget for Xero's Plus tier (~US$160/month) from certification onward.
- Whether you'd sell the app at $5–10k MRR, or run it long-term.
9.3 Definitions used throughout
- Practice: a bookkeeping or accounting business serving several Xero client organisations.
- Connection: one Xero organisation connected to the app by OAuth. Xero's developer tiers are priced by connections.
- Cleanup: a one-off job to fix a client file (recode, void, delete, re-import).
- Reverse: restoring records to their snapshot state. For voids and deletes, "restore as a new copy".
- Paid churn benchmarks: no verified figure for Xero apps. Proxy: Data Fetcher 10% gross, 5% net monthly (founder, 2022).
- Tier A / Tier B: as defined in ../../README.md.