How it works

A sale

1. A sale is paid at the Shopify POS.
2. Shopify notifies zrsPOS. zrsPOS matches each line to a SAGE item by barcode (the EAN on the variant) and builds the document.
3. SAGE issues it in the série you chose for that store. With a NIF, or a Tax Free sale: an FR (invoice-receipt). Without a NIF: an FS (simplified invoice) up to the store's limit (€1,000 unless you set another), an anonymous FR above it — or always an FR if the store is set that way (Settings › Stores).
4. The receipt prints on the till's printer. The document reference is attached to the Shopify order, where staff can reprint, download the A4 or email it.

A return or exchange

• A refund made at the POS issues the returns document you chose for that store (NC or NRE) against the original sale, and prints in the store.
• An exchange at a till issues the credit for what came back and a new sale for what went out; both print on the store's default printer.
• Refunds made from the Shopify admin are issued but never print.

When SAGE is slow or unreachable

The document is queued and retried automatically. The till's Documents tile shows "not issued" while it waits. Never repeat or cancel the sale: the queued document will be issued, and a repeated sale would be invoiced twice. If a document was created in SAGE but the reply never arrived, zrsPOS finds and adopts it instead of issuing a duplicate.

What lives where