Invoice Number Generator
Generate sequential invoice numbers with a custom prefix and format. Set your starting number, choose a format, and copy the numbers directly.
Invoice Number Generator
Generated numbers
Click a number to copy it to clipboard.
Invoice numbering best practices
The ATO requires businesses to keep records of all invoices issued, and a consistent invoice numbering system makes this much easier. Your invoice numbers should be unique, sequential, and traceable.
- Use a consistent prefix (e.g. INV, TAX, 2026)
- Never reuse or skip numbers — gaps raise questions
- Cancelled invoices should be voided, not deleted
- Keep records for at least 5 years (ATO requirement)
- Consider resetting yearly with a year prefix for easy retrieval
Read more: Invoice Numbering Australia — Best Practices for 2026 →
Common numbering formats
Simple
INV-001, INV-002...Best for new businesses. Simple and clean.
Year prefix
INV-2026-001, INV-2026-002...Resets each year. Easier to find invoices by date.
Year + month
INV-202604-001...Maximum traceability. Useful for high-volume invoicing.
Client prefix
ACME-001, SMITH-001...Good for ongoing client relationships.
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