This guide is in English for now. The tool itself works in your language.
Self Invoice › Help › Numbering, printing and saved copies
How self invoice numbers work
Every self invoice gets the next number of its own series, for example SI/26-27/001. Each business has its own series, and it starts again at 1 on 1 April of every financial year.
Step by step
- Let the number fill in. When you start a new self invoice, Self invoice number already shows the next number. Keep it unless you have a reason.
- Change the series if needed. Press Change number series under the number box (or My data › Settings › Number series of each document). Set the prefix; the next number is shown at once.
- Type your own number (optional). You may type a different number, up to 16 letters, numbers, / or -. The maker warns when the same number is already saved for this business and year.
- Save. The series moves on only for numbers you saved.
Worked example
Your first self invoice of 2026-27 is SI/26-27/001, the next SI/26-27/002. On 1 April 2027 the series becomes SI/27-28/001 again with the new year, SI/27-28/001.
Rules and dates
GST documents need a consecutive serial number of up to 16 characters, unique in the financial year, using letters, numbers, hyphen and slash (CGST Rules, rule 46(b) for invoices and the same pattern for notes, receipts and vouchers).
Common mistakes and how to fix them
- Starting each month from 1. Keep one running series for the year; start a new one only on 1 April.
- Two documents with the same number after making them on two computers. Work on one device at a time and move data with a backup file.
- A deleted number leaves a gap. Write the reason in your records (cancelled), or reuse it before the next one is issued.
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