UK accounting and budgeting software
Accounting software designed from day one for HMRC Making Tax Digital (VAT and Income Tax) and RTI payroll.
Live demo
A simplified, self-contained version of the core idea. Everything runs in your browser with sample data.
| Line | Net (£) | Rate |
|---|---|---|
| sale Software licence | ||
| sale Support contract | ||
| sale Child car seats (resale) | ||
| purchase Laptops | ||
| purchase Books |
| Box 1 | VAT due on sales | £3,187.18 |
| Box 2 | VAT due on EU acquisitions (NI) | £0.00 |
| Box 3 | Total VAT due | £3,187.18 |
| Box 4 | VAT reclaimed on purchases | £839.99 |
| Box 5 | Net VAT to pay HMRC | £2,347.19 |
| Box 6 | Total sales ex VAT (whole £) | £16,243.00 |
| Box 7 | Total purchases ex VAT (whole £) | £4,286.00 |
| Box 8 | Supplies to EU (NI) | £0.00 |
| Box 9 | Acquisitions from EU (NI) | £0.00 |
Integer-pence result for Box 1: 318718p. Naive floating-point code gives 3187.1710000000003 — the kind of value that causes penny differences. Our ledger forbids floats for money.
The problem
Small UK businesses must file digitally with HMRC. Software that uses floating-point money or hard-coded tax rules produces penny errors and breaks every April.
Our solution
A modular design: money stored as integer pence and checked by architecture tests that forbid floats, tax rules versioned in YAML with a lock file, a ledger kept separate from HMRC integrations, and a full audit trail. A companion budgeting system adds bank CSV import, reconciliation and reports.
- No-float money rule enforced by tests
- Versioned tax rules (YAML + JSON Schema)
- Compliance map with items to verify
- Desktop shell planned with Tauri
Result
Requirements, compliance analysis, architecture, data model and a seven-phase delivery plan complete; the budgeting system is in its fifth build phase.