If your carrier integration stops working, it is almost always due to changed or expired credentials. Here is how to diagnose and fix it.

Symptoms

  • No services appear when you select a carrier and destination
  • An error appears saying "authentication failed", "invalid credentials", or "unauthorized"
  • Labels that previously worked suddenly fail to create

Step-by-step fix

  1. 1Log in to your carrier portal (PostNord Developer Portal, GLS web, DHL Developer Portal, Mybring)
  2. 2Verify that your API key or credentials are still active — some carriers expire keys or require renewal
  3. 3If the key has expired, generate a new one in the carrier portal
  4. 4Go to Settings → Integrations in ShipCelero
  5. 5Delete the existing carrier connection and re-add it with the updated credentials
  6. 6Try creating a test shipment to verify the connection works

PostNord specifically

PostNord API keys are created in the PostNord Developer Portal. Make sure the API key has access to the Shipping API (not just the tracking API). Your customer number is separate from the API key.

Still not working?

If credentials look correct but the connection still fails, contact us at support@shipcelero.com with the carrier name and the error message you are seeing.