E-invoicing for online retailers
Automate your invoice volume instead of filling in forms by hand: one REST API, one call per order, a finished ZUGFeRD PDF or XRechnung.
Typical challenges
An API instead of manual entry
Use the REST API to create e-invoices directly from your shop or inventory management system: one call per order, no manual form.
Corrections handled properly
Credit notes and invoice corrections are a dedicated invoice type that references the original invoice, not a workaround.
Fraud protection for purchasing
Incoming supplier invoices are validated against KoSIT and examined for manipulated bank details before you pay a wrong IBAN.
Foreign currency at the ECB rate, invoice in English
If you sell to other countries, issue the invoice in the customer's currency. The exchange rate comes from the ECB, VAT is shown additionally in euros, and the invoice is available in English.
OpenAPI description and idempotency against duplicate invoices
The interface is described as OpenAPI 3.1 (for code generators, Postman or Swagger UI). With an idempotency key a repeated call, for example after a network error, does not create a second invoice.
Many invoices from one Excel export
If your shop exports the orders as Excel or CSV, many invoices are created from them at once. Every row is checked before anything is generated. Open items and dunning then show who has not paid yet.
Frequently asked questions: E-invoicing for online retailers
Can I generate e-invoices automatically from my shop?
Yes. Via the REST API (API key authentication) you generate ZUGFeRD PDFs or XRechnung XML directly from your system, without using the web interface.
How do I handle a credit note or cancellation invoice?
As a dedicated invoice type (credit note or correction/cancellation) that references the original invoice number, not as a manually recreated PDF.
What does automation via the API cost?
The same credit prices as in the web interface: creating an invoice costs 1 credit, with no separate API surcharge. Credits do not expire.
Does the service also check my purchase invoices?
Yes, that is actually the core feature on the receiving side: KoSIT validation plus an IBAN fraud check against your supplier history before you trigger a payment.
How do I bill in a foreign currency?
Choose the currency of the invoice. The exchange rate comes from the ECB, as a daily rate or a monthly average, and VAT is shown additionally in euros.
Is there a machine-readable description of the interface?
Yes, at /v1/openapi.json as OpenAPI 3.1 with all paths, fields, data types and allowed values. It is free and needs no API key.
How do I avoid duplicate invoices on retries?
Send an idempotency key with /v1/generate. A repeated call with the same key returns the same response instead of creating a second invoice.