Invoice series and numbering

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Ultimo aggiornamento il 2026-04-21.

Invoice numbering must be consecutive within each series. The name of the series is flexible (for example, A, 2026, POS1), but there must be no gaps within the same series.

If there are two POS systems that cannot maintain consecutive numbering between them, it is recommended to use different series to avoid conflicts. For example, POS 1 can issue invoices in series POS1 (POS1-1, POS1-2, …) and POS 2 in series POS2 (POS2-1, POS2-2, …). In this way, each series maintains its own independent consecutive numbering.

SIMPLIFIED and COMPLETE invoices may be issued within the same series or in separate series. Both options are valid, as long as numbering remains consecutive within the chosen series.

A CORRECTING invoice is issued to rectify an already issued invoice. This type of invoice **must be issued using a specific series, **different from the one used for ordinary invoices. Within this series, the numbering must be sequential. For example, if the original invoice is A-15 and there are no corrective invoices yet, the first corrective invoice could be issued as R-1.

A REMEDY invoice does not create a new invoice but represents a technical correction while preserving the identity of the original invoice. For this reason, a REMEDY must reuse exactly the same series and number values as the original invoice. For example, if the original invoice is A-20, the REMEDY must also be A-20. If athe values do not match, the invoice will be rejected at creation. 

An ENRICHMENT invoice is used to complete a SIMPLIFIED invoice by adding recipient information. An ENRICHMENT invoice is issued as a new invoice linked to the simplified one and therefore must have a different number. It may be issued within the same series or in a different series, as long as numbering remains consecutive. For example, if the original simplified invoice is A-20, the enrichment could be issued as A-21 (or E-1 if a separate series is used). From a practical perspective, the ENRICHMENT invoice “replaces” the simplified invoice for the final, complete version of the document, so there is no need to worry about “duplicating” the original invoice.