Configuring invoice numbering on Shopify

Goal

Configure the invoice number sent in SdI and PEPPOL documents: digits, yearly reset, prefix, suffix, and starting number.

Prerequisites

• Access to Settings > Invoice numbering in the POP for Shopify app.

Steps

In the Invoice numbering card:

1. Number of digits — set the numeric padding (e.g. 4 → the number 13 becomes 0013).
2. Reset the numbers at each year change — if enabled, the counter restarts from 1 on January 1st.
3. Prefix invoice — text before the number (e.g. POP-0013).
4. Suffix — text after the number (e.g. 0013-A); automatically disabled if you use the year as a suffix.
5. Set the year as a suffix — adds the year to the number (e.g. 0013/2025), with a short (/YY) or long (/YYYY) format of your choice.

In the Next available number sub-section you can manually set the next invoice number and the reference year of the progressive (useful after a migration or to align with a numbering already in use elsewhere) and confirm with Apply manually.

Verify

• Generate a test document (in sandbox, see use-sandbox-environment) and check that the invoice number respects the configured digits, prefix, and suffix.
• After manually setting the number, the first document generated must use exactly that number.

Common errors

• “Invoice numbering error: {message}” — invoice number generation failed on POP’s side; retry, and if it persists check that there isn’t a recently set inconsistent manual number.
• The number doesn’t reset at the new year — check that Reset the numbers at each year change is enabled; this setting is independent from the file progressive reset.
• Confusing this numbering with the “file progressive” — invoice numbering is the document’s legal number (SdI/PEPPOL); the file progressive is a separate counter used only in the generated file’s name. See shopify-file-progressive-number.

Related configuration

For the invoice number fields contract in the payload, see api/sdi and api/peppol.