Invoice Number Generator
FreeBuild a compliant invoice number series.
Series preview
INV/2026-27/001
INV/2026-27/002
INV/2026-27/003
INV/2026-27/004
INV/2026-27/005
INV/2026-27/006
INV/2026-27/007
INV/2026-27/008
… up to INV/2026-27/500
GST invoice numbering rules
Under Rule 46 of the CGST Rules, every tax invoice must carry a consecutive serial number, unique for the financial year, that is no more than 16 characters and uses only letters, numbers, hyphens and slashes. Numbers must run in an unbroken sequence.
A common, compliant pattern is PREFIX/FY/0001, for example INV/2026-27/0001. Reset the sequence at the start of each financial year and never reuse or skip a number.
Frequently asked questions
- What is the maximum length of a GST invoice number?
- 16 characters. It may contain letters, digits, hyphens (-) and slashes (/) only, and must be unique within the financial year.
- Do I need to reset invoice numbers each financial year?
- It is standard practice to start a fresh consecutive series each financial year, which is why many businesses embed the FY in the number (e.g. INV/2026-27/0001).
- Can I have multiple invoice series?
- Yes, you can maintain more than one series (e.g. by branch or document type) as long as each is consecutive and unique. Keep prefixes distinct to avoid duplicates.
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