Submit XML: POST /invoices/xml

In plain words

This call submits an invoice that already exists as a finished XML file. It gets a safety check and the route's own validators, and goes to the queue if it passes.

POST /invoices/xml takes a finished UBL, CII or FA(3) file. No mapping happens. The service checks the file for safety and type, runs the official validators for the route, then queues it and sends it unchanged. For FA(3) the checks are the schema plus KSeF's file and date rules.

Note

A 202 means the file passed the safety check and is queued. To check a file before you send it, send the invoice as JSON to POST /validate.

The request

Part	Meaning
`route` query parameter	Required. One of the five routes.
`invoice_ref` query parameter	Required. The ERP's own document id, up to 100 characters.
`client` query parameter	Optional. A client's own key may leave it out or name its own client.
`Idempotency-Key` header	Required, 8 to 100 characters.
`Content-Type` header	`application/xml` or `text/xml`. `application/pdf` is stored and queued the same way.

Which file each route takes:

Route	Accepts
`DE-XRECHNUNG`	UBL, CII
`FR-PA`	UBL, CII
`PEPPOL`	UBL
`RO-EFACTURA`	UBL
`PL-KSEF`	FA(3)

An accepted file

The sample is fa3-pl-ksef.xml, a Polish FA(3) file with invented parties. The state is queued.

curl -X POST "https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PL-KSEF&invoice_ref=INV-2026-0042" \
  -H "Authorization: Bearer <your-api-key>" \
  -H "Content-Type: application/xml" \
  -H "Idempotency-Key: order-2026-0042" \
  --data-binary @fa3-pl-ksef.xml
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.nio.file.Path;

public class Example {
    public static void main(String[] args) throws Exception {
        HttpRequest request = HttpRequest.newBuilder(URI.create("https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PL-KSEF&invoice_ref=INV-2026-0042"))
            .header("Authorization", "Bearer <your-api-key>")
            .header("Content-Type", "application/xml")
            .header("Idempotency-Key", "order-2026-0042")
            .POST(HttpRequest.BodyPublishers.ofFile(Path.of("fa3-pl-ksef.xml")))
            .build();
        HttpResponse<String> response = HttpClient.newHttpClient()
            .send(request, HttpResponse.BodyHandlers.ofString());
        System.out.println(response.statusCode());
        System.out.println(response.body());
    }
}
import { readFile } from 'node:fs/promises';

const response = await fetch('https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PL-KSEF&invoice_ref=INV-2026-0042', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer <your-api-key>',
    'Content-Type': 'application/xml',
    'Idempotency-Key': 'order-2026-0042',
  },
  body: await readFile('fa3-pl-ksef.xml'),
});
console.log(response.status);
console.log(await response.text());

Response202 Accepted

{
  "links": {
    "self": "/invoices/inv_d249e33382ce2911876b7295",
    "events": "/invoices/inv_d249e33382ce2911876b7295/events"
  },
  "id": "inv_d249e33382ce2911876b7295",
  "state": "queued"
}

Recorded on 7 Oct 2026.

A file sent twice

The same file sent again for the same client and route is the invoice already held. The answer carries duplicate_of, the id of the first invoice, and nothing new is sent. A submission that ended rejected, validation_failed or cancelled does not count, so the file can be sent again.

Refused files

XML that is well formed but not an invoice gets 422 with EI-XML-TYPE.

curl -X POST "https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PEPPOL&invoice_ref=INV-2026-0051" \
  -H "Authorization: Bearer <your-api-key>" \
  -H "Content-Type: application/xml" \
  -H "Idempotency-Key: order-2026-0051" \
  --data-binary @not-an-invoice.xml
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.nio.file.Path;

public class Example {
    public static void main(String[] args) throws Exception {
        HttpRequest request = HttpRequest.newBuilder(URI.create("https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PEPPOL&invoice_ref=INV-2026-0051"))
            .header("Authorization", "Bearer <your-api-key>")
            .header("Content-Type", "application/xml")
            .header("Idempotency-Key", "order-2026-0051")
            .POST(HttpRequest.BodyPublishers.ofFile(Path.of("not-an-invoice.xml")))
            .build();
        HttpResponse<String> response = HttpClient.newHttpClient()
            .send(request, HttpResponse.BodyHandlers.ofString());
        System.out.println(response.statusCode());
        System.out.println(response.body());
    }
}
import { readFile } from 'node:fs/promises';

const response = await fetch('https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PEPPOL&invoice_ref=INV-2026-0051', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer <your-api-key>',
    'Content-Type': 'application/xml',
    'Idempotency-Key': 'order-2026-0051',
  },
  body: await readFile('not-an-invoice.xml'),
});
console.log(response.status);
console.log(await response.text());

Response422 Unprocessable Content

{
  "type": "https://eurinvoice.com/problems/validation-failed",
  "title": "The invoice did not pass the checks",
  "errors": [
    {
      "code": "EI-XML-TYPE",
      "fix_hint": "Send the invoice itself, in the format agreed for the route.",
      "who_fixes": "erp",
      "source": "XML-safety",
      "message": "The file is not an invoice in a format this route accepts. Please send the invoice in the agreed format."
    }
  ],
  "status": 422
}

Recorded on 7 Oct 2026. The file is [not-an-invoice.xml](/samples/not-an-invoice.xml).

A file with a DOCTYPE gets 422 with EI-XML-DTD, before any validator reads it. A file that is not well formed gets EI-XML-SYNTAX.

curl -X POST "https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PEPPOL&invoice_ref=INV-2026-0052" \
  -H "Authorization: Bearer <your-api-key>" \
  -H "Content-Type: application/xml" \
  -H "Idempotency-Key: order-2026-0052" \
  --data-binary @with-doctype.xml
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.nio.file.Path;

public class Example {
    public static void main(String[] args) throws Exception {
        HttpRequest request = HttpRequest.newBuilder(URI.create("https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PEPPOL&invoice_ref=INV-2026-0052"))
            .header("Authorization", "Bearer <your-api-key>")
            .header("Content-Type", "application/xml")
            .header("Idempotency-Key", "order-2026-0052")
            .POST(HttpRequest.BodyPublishers.ofFile(Path.of("with-doctype.xml")))
            .build();
        HttpResponse<String> response = HttpClient.newHttpClient()
            .send(request, HttpResponse.BodyHandlers.ofString());
        System.out.println(response.statusCode());
        System.out.println(response.body());
    }
}
import { readFile } from 'node:fs/promises';

const response = await fetch('https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PEPPOL&invoice_ref=INV-2026-0052', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer <your-api-key>',
    'Content-Type': 'application/xml',
    'Idempotency-Key': 'order-2026-0052',
  },
  body: await readFile('with-doctype.xml'),
});
console.log(response.status);
console.log(await response.text());

Response422 Unprocessable Content

{
  "type": "https://eurinvoice.com/problems/validation-failed",
  "title": "The invoice did not pass the checks",
  "errors": [
    {
      "code": "EI-XML-DTD",
      "fix_hint": "Export the invoice without the DOCTYPE line. If the ERP adds one on purpose, raise it with the ERP vendor: no e-invoicing format uses it.",
      "who_fixes": "erp",
      "source": "XML-safety",
      "message": "The invoice file contains a DOCTYPE declaration, which e-invoices never use, so we refused it for security before reading it. Export it again without the DOCTYPE line."
    }
  ],
  "status": 422
}

Recorded on 7 Oct 2026. The file is [with-doctype.xml](/samples/with-doctype.xml).

A content type that is not XML or PDF gets 415.

curl -X POST "https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PEPPOL&invoice_ref=INV-2026-0053" \
  -H "Authorization: Bearer <your-api-key>" \
  -H "Content-Type: text/plain" \
  -H "Idempotency-Key: order-2026-0053" \
  --data-binary @hello.txt
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.nio.file.Path;

public class Example {
    public static void main(String[] args) throws Exception {
        HttpRequest request = HttpRequest.newBuilder(URI.create("https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PEPPOL&invoice_ref=INV-2026-0053"))
            .header("Authorization", "Bearer <your-api-key>")
            .header("Content-Type", "text/plain")
            .header("Idempotency-Key", "order-2026-0053")
            .POST(HttpRequest.BodyPublishers.ofFile(Path.of("hello.txt")))
            .build();
        HttpResponse<String> response = HttpClient.newHttpClient()
            .send(request, HttpResponse.BodyHandlers.ofString());
        System.out.println(response.statusCode());
        System.out.println(response.body());
    }
}
import { readFile } from 'node:fs/promises';

const response = await fetch('https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PEPPOL&invoice_ref=INV-2026-0053', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer <your-api-key>',
    'Content-Type': 'text/plain',
    'Idempotency-Key': 'order-2026-0053',
  },
  body: await readFile('hello.txt'),
});
console.log(response.status);
console.log(await response.text());

Response415 Unsupported Media Type

{
  "type": "https://eurinvoice.com/problems/unsupported-media",
  "title": "Not UBL, CII or FA(3)",
  "status": 415
}

Recorded on 7 Oct 2026.

A missing or short Idempotency-Key gets 400.

curl -X POST "https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PEPPOL&invoice_ref=INV-2026-0054" \
  -H "Authorization: Bearer <your-api-key>" \
  -H "Content-Type: application/xml" \
  --data-binary @ubl-peppol.xml
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.nio.file.Path;

public class Example {
    public static void main(String[] args) throws Exception {
        HttpRequest request = HttpRequest.newBuilder(URI.create("https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PEPPOL&invoice_ref=INV-2026-0054"))
            .header("Authorization", "Bearer <your-api-key>")
            .header("Content-Type", "application/xml")
            .POST(HttpRequest.BodyPublishers.ofFile(Path.of("ubl-peppol.xml")))
            .build();
        HttpResponse<String> response = HttpClient.newHttpClient()
            .send(request, HttpResponse.BodyHandlers.ofString());
        System.out.println(response.statusCode());
        System.out.println(response.body());
    }
}
import { readFile } from 'node:fs/promises';

const response = await fetch('https://api-sandbox-eu.eurinvoice.com/invoices/xml?route=PEPPOL&invoice_ref=INV-2026-0054', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer <your-api-key>',
    'Content-Type': 'application/xml',
  },
  body: await readFile('ubl-peppol.xml'),
});
console.log(response.status);
console.log(await response.text());

Response400 Bad Request

{
  "detail": "Idempotency-Key must be between 8 and 100 characters.",
  "type": "https://eurinvoice.com/problems/bad-request",
  "title": "The request could not be read",
  "status": 400
}

Recorded on 7 Oct 2026.

Answers

Status	Meaning
`202`	Accepted and queued. `Location` holds the invoice URL.
`400`	A query parameter or the `Idempotency-Key` is missing or wrong.
`401`	No key, or an unknown key.
`403`	The key lacks the `submit` scope, or names another client (`forbidden`).
`409`	The key was used with a different body (`idempotency-conflict`), or its first request is still running (`request-in-progress`).
`413`	The body is over 5 MB (`payload-too-large`).
`415`	The content type is not XML or PDF (`unsupported-media`).
`422`	A refused file: `EI-XML-DTD`, `EI-XML-SYNTAX` or `EI-XML-TYPE`.
`429`	Too many requests for the key. Wait for `Retry-After` seconds.
`503`	Another request for the same document is still being stored (`busy`). Retry after `Retry-After` seconds.

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A file sent twiceCopy the link to this section

Refused filesCopy the link to this section

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The request

An accepted file

A file sent twice

Refused files

Answers