Turn a Google Sheet row into an XRechnung and email it

Since January 2025 our public-sector clients stopped accepting PDF invoices — they want XRechnung XML (EN 16931) or they don't pay. We're a four-person consultancy; I handle the admin side on top of my actual work, and I wasn't keen to learn a new invoicing tool just to be compliant. Our outgoing invoices have lived in a Google Sheet for years: one row per invoice, one tab per fiscal year.

This workflow reads the rows where status = pending, generates an XRechnung XML for each via invoice-api.xhub, emails it to the buyer with a short cover message, and flips the row to status = sent with a timestamp. I run it manually on the 1st and the 15th; swapping the Manual Trigger for a Schedule Trigger is a one-click change.

The Code node in the middle is the interesting bit. It maps whatever column style you use — invoiceNumber and invoice_number both work — into the JSON the API expects, and it derives net, VAT and gross from unit price × quantity × rate so I don't have to keep those columns in sync by hand. Single-line invoices fit comfortably in a row; multi-line cases need a small tweak of the mapper.

What you need

• An invoice-api.xhub API key (free sandbox keys start with sk_test_)
• A Google Sheet with the columns shown in 02-generate-xrechnung-from-sheets-example.csv — copy it into a tab named Invoices
• Gmail for the send step (any other mail integration drops in where Gmail is today)

Switching countries

Set Config has countryCode and format fields. Default is DE / xrechnung. Change to FR / facturx, IT / fatturapa, and so on — the rest of the workflow doesn't care.