Invoice numbering

Every invoice and credit note you issue from Financica receives a sequential number from a numbering series. Numbers are gapless within a series and unique across your company, which is what VAT law asks for (in Belgium, Royal Decree n°1, art. 5: "a sequential number, based on one or more series, that identifies the invoice uniquely").

When a number is assigned

A draft has no number yet. The number is assigned the moment the document is finalized: when you approve it, mark it as sent, send it by email, or send it via Peppol. That is deliberate: a draft you delete leaves no hole in the sequence.

Until then, the invoice form and the invoice page show the number the document will get, so you know what to expect. Two drafts can show the same upcoming number; the first one finalized takes it.

Once assigned, the number cannot be edited. To cancel a numbered invoice, void it or issue a credit note.

Numbers that arrive with a document (Stripe invoices, invoices received via Peppol, imported invoices, supplier invoices) are kept as they are; the series only apply to documents you author in Financica.

The number format

Numbers look like PREFIX-0001, and follow your settings:

• CN- marker for credit notes: CN-PREFIX-0001. Credit notes run their own counter, so CN-PREFIX-0001 is the first credit note, not a credit note on invoice 0001. The credit note still references the invoice it corrects.
• Year, when yearly reset is on: PREFIX-2026-0001. The counter restarts every year and the year comes from the invoice's issue date, so an invoice dated in December stays in last year's series even if you finalize it in January.
• Counter digits: how many digits the counter is padded to (0001 with 4).

One series, or one per customer

Under Settings > Organization > Accounting > Invoice numbering you choose:

• One series for the whole company: every document continues the same counter under your prefix (for example ACME-0001, ACME-0002).
• One series per customer: each customer has its own prefix and its own counter (ACME-0001 for one customer, 9F2C1B7A-0001 for another). Every customer's series is gapless on its own.

Per-customer prefixes default to a short code derived from the customer. You can replace it with anything you like on the customer's page (Invoice prefix), for example the customer's short name. Prefixes are letters, digits and dashes, and must be unique among your customers.

Changing any of these settings only affects numbers assigned from then on. Existing numbers never change; a new prefix, or turning yearly reset on, simply starts a new series.

Continuing numbering from another tool

If you already issued invoices this year in another system, you do not have to start at 1. Under Settings > Organization > Advanced > Invoice number series you can see every series with how many numbers it issued and what the next number will be, and move a counter forward. You can also start a series at a given number before its first invoice, for example 2026 invoices from 143 onwards.

Counters only move forward. Moving one back would reuse numbers, which is exactly what an audit checks for.