Benford 1st Digit
Test whether amounts follow the natural distribution that occurs when numbers arise organically.
- General ledger alone
What it checks
- Population spans several orders of magnitude, free of imposed floors, ceilings and price points.
- Assigned numbers — account codes, references, anything sequential — are excluded.
- Conformity judged on MAD; the digit-level z-score only says where the break sits.
How the result is read
The test is only valid on a population that could have been Benford in the first place: amounts capped by an approval limit or driven by a price list are non-conformant by construction. Conformity is therefore assessed on mean absolute deviation, which does not move with sample size — a chi-square or z-score rejects at every digit on a full ledger and the test degenerates into flagging everything.
The worksheet, on the demo engagement
Benford 1st Digit, as the application draws it for Harrow Precision Engineering Ltd, the fictional demo engagement — one row per leading digit, 1 to 9.
- Observed
- Benford ±2pp
- Outside band
Band is ±2pp around expectation. Marked digits fall outside it; the entries behind them are the population to open.
- n
- 188,402
- Chi-square
- 412.6
- MAD
- 0.018
MAD 0.018 = non-conformity. Digit-2 spike (round plugs near 2,000-2,950) drives the break.
Result grid6 of 9 rows
| First digit | Observed % | Expected % | Z-score | Flag |
|---|---|---|---|---|
| 1 | 28.9% | 30.1% | 1.6 | |
| 2 | 24.1% | 17.6% | +9.4 | Z>1.96 (pairs 24) |
| 3 | 11.0% | 12.5% | 1.9 | |
| 4 | 11.8% | 9.7% | +4.2 | pairs 24, 49 |
| 5 | 6.0% | 7.9% | 3.1 | Z>1.96 |
| 6 | 6.1% | 6.7% | 1.0 |
In the application
Benford 1st Digit is filed under Journal entries, index letter B. "Run all analyses" runs it with every other analysis the ledger can answer. The worksheet states the population it tested on its face — or "Not applicable" with the reason when a column it depends on is empty — and the Excel workbook the engagement exports files it under B, beside an index of the source files with their SHA-256 fingerprints.
Read it with
Run your next audit file test without the Excel crash.
One free engagement to evaluate, valid 60 days. The ledger never leaves the machine.
- 20 minutes
- Runs on a fictional engagement
- No client data required