How does Peppol e-invoicing send an invoice electronically?

Peppol sends an invoice through four corners. An access point, or AP, is a certified provider that connects a company to the network. Here, Bright Supplies invoices Northwind Retail for 1,200 euros, and each company uses its own AP.

Invoice INV-1042 isn't a PDF. Bright's accounting system exports its fields, like 1,000 euros net, 200 euros VAT, and the buyer's ID, as standard UBL XML. Then validation checks it, so the access point can reject errors before anything is sent.

Now the supplier's access point needs Northwind's address. It sends Northwind's Peppol ID to the SML, which says where the right SMP is. The SMP then returns Northwind's access point address, plus the document formats it accepts. Only then can the invoice be sent.

Now Bright's access point sends INV-1042 to Northwind's access point, signed and encrypted using the AS4 protocol. Northwind's access point returns a receipt, proving delivery. Then it hands the data to Northwind's system, which reads the EUR 1,200 total automatically. No retyping needed.

If Northwind switches to a different access point provider, what must Bright Supplies change to keep sending invoices?

Nothing; the lookup finds the new access point. Northwind updates its registration in the SMP, and Bright's access point looks up the address every time it sends. Suppliers never hard-wire a buyer's provider, so switching is invisible to them.

Think of access points as post offices. Each business connects to just one, and the offices exchange sealed envelopes of structured invoice data. Bright never needs a direct link to Northwind. One connection reaches every registered buyer on the network.

In practice, Northwind's system reads INV-1042 without retyping, and errors are caught before it leaves. To join, you need a Peppol ID and an access point. Some countries add tax reporting rules.

Mental model unseen, so in short: Peppol connects any supplier to any registered buyer through access points. INV-1042 left Bright as structured data, was looked up, sent securely, confirmed, and imported into Northwind automatically.