Paste invoice, credit note or voucher numbers, one per line. The tool groups them into series by the text before the final number, then lists missing numbers and numbers used twice. A gap is a question for the client, not a finding.
Each series is the text before the last run of digits, so INV/26-27/ and CN/26-27/ are tested separately. Gaps are looked for only between the lowest and highest number seen. A number missing at the start or end of the year will not show, so compare the first and last numbers with the client's records.
| Series | Count | First | Last | Missing | Missing ranges | Repeated |
|---|---|---|---|---|---|---|
| INV/26-27/ | 7 | INV/26-27/0001 | INV/26-27/0010 | 4 | INV/26-27/0004 to INV/26-27/0005; INV/26-27/0008 to INV/26-27/0009 | INV/26-27/0007 |
| CN/26-27/ | 3 | CN/26-27/001 | CN/26-27/004 | 1 | CN/26-27/003 |
Lines without a trailing number: Cancelled.
Invoices are meant to run in an unbroken series. A missing number can be a cancelled invoice, a test entry, a voided print, or a sale that was left out of the books. A repeated number can be a reissue or a second invoice under the same number. Ask for the cancelled copy or the explanation for each gap, and check that cancelled documents were reported correctly. Check the current invoice numbering rules that apply to your client.
Each number is split into a prefix and the final run of digits. Numbers with the same prefix form a series, so invoices and credit notes are checked on their own.
Within a series the digits are sorted. A jump of more than one between neighbours is a gap, and the numbers skipped are listed. Two equal numbers are reported as repeated.
Zero padding is kept when the numbers are shown again. Lines that do not end in a number are listed but not tested.
Invoice numbers 1, 2, 3, 6, 7, 7 and 10 in one series.
