Which formats are supported?

ZUGFeRD in the EN 16931 profile (also known as Factur-X), a PDF/A-3 with the XML embedded, and XRechnung 3.0 as XML in CII syntax. You pick the format per automation.

How is the e-invoice checked?

Every file is checked before it goes out: XRechnung with the KoSIT validator, ZUGFeRD with Mustang. We also recalculate lines, tax and total. If a check fails, no file is created and the message names the field.

You do not need one. The API is one HTTP call with JSON and a Bearer token, from any language and any backend. Make and Zapier have their own DocsAutomator apps, and n8n has a community node.

What are the rate limits?

Each API key belongs to a workspace and has its own rate limit. For many invoices at once, use async mode: you get a job ID right away and, if you want, a webhook when the file is ready.

Can I change the layout per customer?

Yes. Create a template per layout and pick it in the request with the docId. Within one template, conditions control content, such as a note only for certain customers.

New: Approvals. Your team approves documents before they go out.Learn more

HomeFeaturesE-InvoicingAPI

Required for B2B in Germany: from 1 Jan 2027 above €800,000 turnover, from 1 Jan 2028 for almost all

ZUGFeRD & XRechnung API

JSON in, checked e-invoice out. Layout from your Google Docs template, EN 16931 checks included. For SaaS, marketplaces and your own apps.

Get an API key Done-for-you setup

Works with Lovable, Bolt, Cursor and any backend.

Diese Seite auf Deutsch

How it works

1
Set up a template
Create an automation with your invoice template, switch on e-invoices and pick ZUGFeRD or XRechnung.
```
POST /createDocument
{
  "invoice_number": "RE-0142",
  "customer_name": "Muster",
  "line_items_1": [ … ]
}
```
2
POST the invoice data
Send customer, invoice number, date and line items as JSON to /createDocument, with your API key as the Bearer token.
200 OK · checked
```
{
  "pdfUrl": "…/RE-0142.pdf"
}
```
3
Get the e-invoice back
The response points to the checked ZUGFeRD PDF or XRechnung XML. In async mode you get a job ID and, if you want, a webhook.

E-invoices need a DocsAutomator subscription. You can set everything up and test it for free, and only pay once you go live. See pricing

One request, one e-invoice

The field names in data are the placeholders of your template. Line items go in as a list, such as line_items_1.

curl -X POST https://api.docsautomator.co/createDocument \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "docId": "YOUR_AUTOMATION_ID",
    "data": {
      "invoice_number": "RE-2026-0142",
      "invoice_date": "2026-10-12",
      "customer_name": "Muster Gartenbau GmbH",
      "customer_vat_id": "DE123456789",
      "line_items_1": [
        { "description": "Beratung", "quantity": 3, "unit_price": 120, "tax_rate": 19 },
        { "description": "Konzept", "quantity": 1, "unit_price": 540, "tax_rate": 19 }
      ]
    }
  }'

API documentation

What you get back

A ZUGFeRD invoice: the PDF from your template, with the invoice data inside as XML under EN 16931.

The PDF for your customerEN 16931 checked

Beispiel Studio GmbH

Invoice

Beispiel Studio GmbH · Hauptstraße 12 · 10115 Berlin

Muster Gartenbau GmbHGartenweg 550667 Köln

Invoice no.: RE-2026-0142
Date: 2026-10-12
Service: 2026-09-30
Due: 2026-10-26

DescriptionQtyAmount

Consulting3 h × €120.00€360.00

Concept1 × €540.00€540.00

Net€900.00

VAT 19%€171.00

Total€1,071.00

VAT ID DE123456789 · IBAN DE00 0000 0000 0000 0000 00

RE-2026-0142.pdf · ZUGFeRD, PDF/A-3

The XML inside, for their accounting software

<rsm:CrossIndustryInvoice>
  <rsm:ExchangedDocumentContext>
    <ram:GuidelineSpecifiedDocumentContextParameter>
      <ram:ID>urn:cen.eu:en16931:2017</ram:ID>
    </ram:GuidelineSpecifiedDocumentContextParameter>
  </rsm:ExchangedDocumentContext>
  <rsm:ExchangedDocument>
    <ram:ID>RE-2026-0142</ram:ID>
    <ram:TypeCode>380</ram:TypeCode>
    <ram:IssueDateTime>
      <udt:DateTimeString format="102">20261012</udt:DateTimeString>
    </ram:IssueDateTime>
  </rsm:ExchangedDocument>
  …
  <ram:SpecifiedTradeSettlementHeaderMonetarySummation>
    <ram:TaxBasisTotalAmount>900.00</ram:TaxBasisTotalAmount>
    <ram:TaxTotalAmount currencyID="EUR">171.00</ram:TaxTotalAmount>
    <ram:GrandTotalAmount>1071.00</ram:GrandTotalAmount>
  </ram:SpecifiedTradeSettlementHeaderMonetarySummation>
</rsm:CrossIndustryInvoice>

Example with made-up data. The XML is shortened.