Account setup

Create your Verified Account, add a payment method, and connect your integration.

Step 1 — Create your Verified Account

Register for a Zonos Verified Account using the Česká pošta registration link. Complete your business address and billing setup.

Step 2 — Add a payment method

Add a payment method to your Zonos account to fund duty remittance for U.S.-bound shipments.

Step 3 — Get your API key

Name in Dashboard↕	Purpose↕	Use for the API?↕
Account key	Identifier for linking with the postal operator	❌ NO
API key	Authentication key for calling the Zonos API	✅ YES — use this one

Copy the token in the API key row. It begins with credential_live_. You will need this key for both integration methods.

Keep your API key secure. Do not commit it to source control or share it publicly. If you believe it has been compromised, regenerate it from the same Account → Integrations page.

Step 4 (optional) — Estimate duty costs with Item Quoter

The Item Quoter tool in your Zonos Dashboard lets you look up estimated duty costs for your products before shipping — useful for checking rates and planning ahead without generating a Declaration ID.

Integration methods

Choose the method that fits your technical setup. Both methods produce Declaration IDs that you then upload to Česká pošta's shipping system.

For technical customers and developers who call Zonos directly from their own system.

Endpoint

URL: https://api.zonos.com/graphql
Method: POST
Content-Type: application/json

Authentication

Pass your API key in the credentialToken header: credentialToken: credential_live_xxxxxxxxxxxxxxxxxx

API example

After generating Declaration IDs

Submit the Declaration ID to Česká pošta along with your shipment details. Česká pošta links the Declaration ID to the shipment and returns a tracking number. Zonos does not issue tracking numbers.

Error handling

Error / Symptom↕	Likely cause and fix↕
Security requirement failed	Your API key is invalid or passed in the wrong header. Ensure you're using the API Key (not the Account Key) and the header name is exactly `credentialToken`.
HTTP 401 Unauthorized	The API key is missing from the request headers. Confirm `credentialToken` is included.
`errors` array in response	The mutation returned a GraphQL error. Check the `message` field in the errors array for details.
Unexpected response shape	The response did not include `data.declarationCreate.id`. Log the full response body and verify the mutation text matches the example exactly.

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