How it's built

Our tax numbers aren't typed in. They're tested.

Most business software shows you a GST or tax figure and asks you to trust it. Here's what actually stands behind the numbers Momentum shows you — not a claim, a description of the tests that run before any of it ships.

409Automated tax & GST assertions

5Independent revenue paths, reconciled to the cent

17Expense categories, each with its own GST + deduction rule

Every number comes from one engine, not five

A weekly revenue figure, a BAS estimate and a client's pack balance can each be calculated from the same underlying sessions — and in most software, they're calculated by different code that was written at different times. That's how a dashboard, a report and an invoice quietly disagree with each other.

Momentum went through exactly that problem and fixed it: every place revenue is calculated — the weekly grid, the dashboard, the BAS worksheet, the client report, the date-range report — now calls one shared function. There is nowhere left for the numbers to drift apart, because there's only one calculation to drift from.

What the reconciliation harness actually checks

An automated test builds one adversarial week — mixed rate types, a 2:1 session, a paid cancellation, a make-up session, an archived client — and runs it through every single one of those five paths independently. The test fails unless all five land on the exact same dollar figure. It has been run on every change since it was written.

What 409 assertions actually cover

"409 tests" is a hollow number on its own, so here's what a sample of them actually check, each against known-correct ATO figures:

GST collected and GST credits are correctly split by expense category — a home-office phone bill and a gym insurance premium are treated differently, on purpose
The Medicare levy shade-in band (10c/$ between the two thresholds) matches the legislated formula exactly, not an approximation
The Low Income Tax Offset tapers in two stages and is never applied to reduce the Medicare levy itself, which is a common calculation mistake
A 2:1 session is billed at half the normal rate — but only for the partner-aware case, not blanket-halved, which is a subtler rule than it sounds
A paid cancellation still counts as revenue and still deducts the prepaid credit — so the pack balance and the revenue figure can never disagree
Superannuation contributions reduce taxable profit correctly, capped at the concessional limit

What this page is deliberately not saying

This is a description of testing rigor, not a tax opinion

Passing 409 tests proves the arithmetic is consistent and matches the rules as we understand them. It does not, on its own, make a judgement call like "is this specific expense deductible for your business" — those calls are still estimates, and the app labels them that way throughout. Momentum Tracking is not a registered tax agent, and nothing here is tax advice.

The specific category-by-category GST and deduction defaults the app ships with are separately under review by a registered BAS agent. This page is about how the engine computes whatever rules it's given — not a claim that every default is the last word. Always confirm your own position with a registered tax or BAS agent.

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