WooCommerce order → XRechnung → email the buyer, note the order

My shop sells lab consumables — pipette tips, reagent bottles, filter papers — mostly to university institutes, clinics, and the occasional research foundation. They're all publicly funded, and since early 2025 their procurement desks have been bouncing our order-confirmation emails because a plain PDF isn't a compliant e-invoice any more. Support tickets were piling up. This workflow is how I cleared them.

Every new WooCommerce order triggers the flow. A Code node maps the order — line items, billing address, currency, totals — into the JSON invoice-api.xhub expects, the API generates the XRechnung XML, Gmail attaches it to a short mail to the billing email, and an internal note is added to the WooCommerce order so my future self knows the XRechnung went out.

The one-time config lives in Set Config: your company name, VAT ID, invoicing email, street, city, postcode, country, and the default VAT rate. I left vatRate at 19 because it covers most of my catalogue — see Limitations below if yours is mixed.

Connecting WooCommerce

You need the REST API credentials from the shop (WooCommerce → Settings → Advanced → REST API, Consumer Key / Secret). Read access is enough: this workflow only reads the order for mapping, and the confirmation note is written via the n8n WooCommerce node rather than a raw API call.

Limitations

Single VAT rate per order. If your catalogue mixes 7% and 19% — books, food, printed matter — this template flattens them to one rate, which is wrong for a proper XRechnung. The fix is small (derive vatRate per line item instead of from Set Config), but I didn't need it and so didn't build it. Reduced-rate and reverse-charge scenarios aren't modelled either; those tend to want a human in the loop anyway.