Small Business Invoice Numbering with Custom Formats

Set invoice numbering while creating a new invoice: click Format beside the invoice-number field, choose a preset or custom format, review the next-number preview and apply it. Each saved format remembers its own last invoice.

The main benefit is maintaining multiple sequences at once. Use INV-2026-001 for standard invoices and ONLINE-2026-001 for online-store orders. Branches and other sales channels can be separated in the same way, with each format continuing independently from its last number.

The CTA below opens the new-invoice form with the Format picker already displayed. The normal path is New invoice, then Format beside the invoice number. Numbers created outside Simple Invoicing still need to be checked against your complete business records.

Where to set a small business invoice number format

The format picker is attached to the invoice-number field in the new-invoice form.

1. 1

   Click Format beside the invoice number

   Open New invoice and use the Format button next to the invoice-number field. The direct CTA on this page opens the same form and displays the picker automatically.

2. 2

   Choose Presets or Custom format

   Use a ready-made preset, or combine year, month, separators and one sequence in Custom format. Add a custom text token to create a prefix such as INV, ONLINE or a branch code.

3. 3

   Check Preview and click Apply

   The picker calculates the next number for the selected format. Apply inserts it into the invoice and links the saved document to that format so its sequence can continue next time.

Create a custom prefix and format

In the Custom format tab, add tokens by clicking them. Use the custom text token for a prefix or suffix such as INV, ONLINE or a branch code, then add year, optional month, separators and one NN, NNN or NNNN sequence.

Preview updates while you build. After you apply the format and save the invoice, that format is available from recent History. A frequently used format can also be selected as the account default.

• Use NN, NNN or NNNN for the expected capacity.
• Choose one separator style and retain it.
• Preview the first invoice after a date change.
• Search existing records after imports or system changes.

Keep several sequences moving independently

Invoices retain the format used to create their numbers. When you select that format again, Simple Invoicing finds its last compatible invoice and increments that specific sequence. Using INV does not advance ONLINE, even when both belong to the same account.

Copied, imported and externally created invoices still need review. The app cannot see a PDF or number stored only in another system, so compare proposed values against the complete records when changing tools.

Automation does not replace recordkeeping

A saved format reduces inconsistent typing. It cannot detect a PDF created outside the app, design your correction process, or decide whether multiple business units need separate series. Those are recordkeeping decisions for your business and advisers.

Manual changes remain possible, so review every final PDF. If you discover a duplicate after issuing documents, do not silently rename archived copies; handle the correction consistently with your records.

Related guides and tools

Frequently asked questions