Gap Test
Definition
A test that identifies missing numbers in a document sequence (check numbers, invoice series, purchase orders) where continuity is expected; gaps often indicate documents that were destroyed or never recorded.
- Purpose
- Identifies missing numbers in a document sequence
- Applies to
- Check numbers, invoice series, purchase orders
- Field
- Computer-assisted audit techniques
- Common finding
- Gaps suggest destroyed or unrecorded documents
Common questions
How is a gap test actually run against a large dataset?+
The auditor sorts the sequence field, such as invoice or check number, and programmatically compares each value to the one before it, flagging any interval greater than one; CAAT tools automate this so gaps across tens of thousands of records surface in a single pass.
Does a gap always mean fraud?+
No. Voided checks, cancelled orders, or numbers reserved for a different location or system can produce legitimate gaps, so a gap test result is a lead requiring follow-up against source documentation, not a finding on its own.
How does a gap test differ from a duplicate test in CAAT work?+
A gap test looks for numbers that are missing from an expected sequence, pointing to records that may never have been created or were removed, while a duplicate test looks for the same number or transaction appearing more than once, pointing to double payment or record manipulation.
Related terms
- CAATs
- Computer-Assisted Audit Techniques: software-driven procedures applied to electronic data files that test the full population of transactions rather than a sample, covering...
- Duplicate Detection
- A systematic search for records that share key fields (invoice number, vendor, amount, date) that should be unique, surfacing duplicate payments, double...
- Join-and-Match
- A cross-table technique that links two or more data files on a common key, such as matching vendor bank account numbers against...
- Ratio Analysis
- Calculation of financial ratios across periods or business units to identify statistically unusual deviations that might indicate manipulation: cost ratios, gross margin...
- Sequence Analysis
- Verification that a numbered series progresses in expected order without skips, reversals, or unexpected repetitions. It is the positive counterpart to gap...
- Stratification
- The grouping of numeric values into defined ranges (strata) to reveal the distribution of a dataset. In fraud detection, large concentrations of...