Send invoices (end-to-end)

This guide shows a clean API flow to send invoices: create or reuse a contact, create or import an invoice, send it, and retrieve the final files.

Prerequisites

API Key: X-B2B-API-Key
API Version: X-B2B-API-Version
ACCOUNT_ID: the account that issues the invoice.

Important IDs:

ACCOUNT_ID: owner account (path param in /accounts/{ACCOUNT_ID}/...).
CONTACT_ID: recipient contact (stored inside the account).
INVOICE_ID: invoice identifier (used in /invoices/{INVOICE_ID}... endpoints).

1) Get or create the recipient contact

1.1) Lookup contacts (optional)

curl --request GET \
  --url 'https://api-staging.b2brouter.net/accounts/{ACCOUNT_ID}/contacts?offset=0&limit=25&name=Example%20Customer' \
  --header 'X-B2B-API-Key: {YOUR_API_KEY}' \
  --header 'X-B2B-API-Version: {YOUR_API_VERSION}' \
  --header 'accept: application/json'

1.2) Lookup in the directory (optional)

If you know the recipient’s identifier and country, you can retrieve public information from the directory and use it to build the contact.

curl --request GET \
  --url https://api-staging.b2brouter.net/directory/es/ESB63276174 \
  --header 'X-B2B-API-Key: {YOUR_API_KEY}' \
  --header 'X-B2B-API-Version: {YOUR_API_VERSION}' \
  --header 'accept: application/json'

1.3) Create a contact (if you don’t have one)

curl --request POST \
  --url https://api-staging.b2brouter.net/accounts/{ACCOUNT_ID}/contacts \
  --header 'X-B2B-API-Key: {YOUR_API_KEY}' \
  --header 'X-B2B-API-Version: {YOUR_API_VERSION}' \
  --header 'accept: application/json' \
  --header 'content-type: application/json' \
  --data '{
    "contact": {
      "name": "Example Customer",
      "country": "es",
      "is_client": true,
      "email": "[email protected]",
      "tin_scheme": "9920",
      "tin_value": "ESB00000000",
      "transport_type_code": "b2brouter",
      "document_type_code": "json"
    }
  }'

Note: CONTACT_ID is returned in the response. Do not confuse it with ACCOUNT_ID.

2) Create (JSON) or import (XML) the invoice

2.1) Create invoice using JSON

curl --request POST \
  --url https://api-staging.b2brouter.net/accounts/{ACCOUNT_ID}/invoices \
  --header 'X-B2B-API-Key: {YOUR_API_KEY}' \
  --header 'X-B2B-API-Version: {YOUR_API_VERSION}' \
  --header 'accept: application/json' \
  --header 'content-type: application/json' \
  --data '{
    "send_after_import": false,
    "invoice": {
      "type": "IssuedInvoice",
      "contact_id": {CONTACT_ID},
      "number": "INV-0001",
      "date": "2026-01-21",
      "terms": "custom",
      "due_date": "2026-02-21",
      "currency": "EUR",
      "invoice_lines_attributes": [
        {
          "quantity": 1,
          "price": 10,
          "description": "Example service",
          "taxes_attributes": [
            { "name": "VAT", "category": "S", "percent": 21 }
          ]
        }
      ]
    }
  }'

2.2) Import invoice from a file (when you already generate XML)

curl --request POST \
  --url 'https://api-staging.b2brouter.net/accounts/{ACCOUNT_ID}/invoices/import?send_after_import=false' \
  --header 'X-B2B-API-Key: {YOUR_API_KEY}' \
  --header 'X-B2B-API-Version: {YOUR_API_VERSION}' \
  --header 'content-type: application/octet-stream' \
  --data 'data:text/xml;name=invoice.xml;base64,PD94bWw+Li4u'

3) Send the invoice

curl --request POST \
  --url https://api-staging.b2brouter.net/invoices/send_invoice/{INVOICE_ID} \
  --header 'X-B2B-API-Key: {YOUR_API_KEY}' \
  --header 'X-B2B-API-Version: {YOUR_API_VERSION}'

4) Retrieve the invoice and download final files

4.1) Get the invoice payload

curl --request GET \
  --url https://api-staging.b2brouter.net/invoices/{INVOICE_ID}?include=lines \
  --header 'X-B2B-API-Key: {YOUR_API_KEY}' \
  --header 'X-B2B-API-Version: {YOUR_API_VERSION}' \
  --header 'accept: application/json'

4.2) Download legal/original invoice files

Follow: https://developer.b2brouter.net/docs/download_legal_or_original_invoice

Related guides

Payment methods: https://developer.b2brouter.net/docs/payment_method_guide#/
Invoice calculation: https://developer.b2brouter.net/docs/invoice_calculation#/
Send invoice via JSON (Peppol example): https://developer.b2brouter.net/docs/send_an_invoice_through_peppol_via_json_payload#/