General ledger errors hide in patterns more than in single entries: journals entered twice, revenue booked by hand, manual entries on the last day of the month, round amounts, accounts that rarely meet, and balances on the wrong side. Test for those patterns every month, look at each hit in context, and fix what is wrong with a reversing or correcting entry that someone approves, never by editing the original.
What kinds of errors end up in a general ledger?
- Errors of omission: a bill, accrual or depreciation run never posted.
- Errors of duplication: the same invoice or journal entered twice.
- Errors of classification: a cost on the wrong account, an asset expensed, revenue in the wrong company.
- Errors of period: an entry dated in the wrong month or year.
- Errors of amount: a transposed or mistyped figure, or the wrong exchange rate.
- Entries that need a second look: manual journals to revenue, bank, equity or tax, and anything approved by the person who entered it.
Which patterns point to an error?
| Pattern | Why it matters | How to test it |
|---|---|---|
| Entries that look entered twice | Double costs or double revenue | Same accounts, amounts and party within a few days |
| Unusual account pairs | A debit and credit that rarely meet may be a misposting | Pairs seen once between two busy accounts, of kinds that rarely meet |
| Revenue booked by hand | Revenue normally comes from invoices | Manual journals that credit revenue accounts |
| Manual journals on the last day | Late adjustments are where mistakes and pressure meet | Manual entries on the final day of a month or year |
| Round amounts | Estimates presented as facts | Large entries ending in 000 |
| Unusually large entries | One entry can move the month | The largest entries against the usual size |
| Weekend or after-hours entries | Outside normal review | Manual entries outside working days and hours |
| Balances on the wrong side | Misposting or a missing reclassification | Assets in credit, liabilities in debit |
| Self-approved entries | No second pair of eyes | Entries approved by the person who entered them |
How do you review what the tests find?
- Open the whole entryLook at every line, the description, the party and the attachment, not only the flagged line.
- Check the contextCompare with the same entry in earlier months and with the source document.
- DecideMark it fine with a reason, assign it to the person who can explain it, or prepare a correction.
- Correct with a new entryReverse or adjust with a new journal that is approved like any other, so the audit trail shows both.
- Stop it recurringIf the same pattern keeps appearing, fix the cause: a mapping, a template, an interface or a missing control.
How often should the ledger be tested?
Every month before the close is signed off, and on every new entry if the tests can run automatically. Testing only at year end leaves twelve months of errors for the auditors to find. See the 25 financial data quality checks for the checks on the data itself.
Questions people ask
Is every flagged entry an error?
No. A pattern means "look at this". Many flagged entries are correct; the review records why.
Should we edit the wrong entry in the ERP?
No. Post a reversing or correcting entry, approved like any other, so the audit trail keeps both.
Which test finds the most errors?
Duplicate entries and unmapped or misclassified accounts usually account for most of what changes the reported numbers.
Do these tests replace internal audit?
No. They make the ledger cleaner before internal and external audit look at it.