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The Postal Company API

The Postal Company API lets you send physical letters anywhere in the world from your application. Write your letter content, provide a recipient address, and we handle printing, enveloping, and postal delivery.

Quick start

1

Create an account

Sign up at thepostalcompany.com and log in to your dashboard.
2

Top up your balance

Go to the Balance page and purchase credits. Each letter costs €2.50.
3

Create an API key

Go to API Keys and create a new key. Copy it — it’s only shown once.
4

Send a letter

curl -X POST https://thepostalcompany.com/api/v1/letters \
  -H "Authorization: Bearer tpc_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "recipient": "Jane Doe",
    "address": {
      "street": "Keizersgracht",
      "number": "123",
      "postalcode": "1015 CJ",
      "city": "Amsterdam",
      "country": "NL"
    },
    "content": "Dear Jane,\n\nThis is a test letter sent via the API.\n\nBest regards"
  }'

Key concepts

  • Credits — Pre-paid balance used to send letters. Each letter costs €2.50.
  • API keys — Long-lived keys for authenticating API requests. You can create multiple keys and revoke them at any time.
  • Letters — Once submitted, letters are queued for printing and postal delivery. The API returns a letter ID you can use for tracking.