This error occurs when the API Token saved in the plugin is not correct or if the Smart Send account has been closed.

  1. Login to your account and verify that you have a valid subscription
  2. Check that the API Token in the plugin is correct. The API Token was sent to you in you welcome email, and can also be found in your account here

The error message will tell you both what URL you have currently trying to use the API Token for and what URL you have registred on your Smart Send account.

These URLs have to be 100% identical before the API token will work.

To change the URL of the website go the the settings page.


This error usually occurs when you are trying to use a feature you do not have access to.

This can either be because your trial has expired or you are on a Standard subscription and trying to use a feature that require Professional subscription.

  1. Login to your account
  2. Select billing in the top right menu
  3. Verify that you have an active subscription covering the requested feature
  4. Upgrade to one of the subscription plans that include the requested feature


We were unable to book the shipment with the carrier. This is usually because of incorrect data or the carrier is experiencing problems with their IT.


This error occurs when the carrier credentials entered in the Smart Send user profile is invalid. This usually occur if the carrier password has been changed.

To solve this update the carrier account information in the Smart Send user profile:

Enter valid credentials for the carrier you are trying to generate labels for

This means that


The data provided failed validation.

This error occurs, when the data provided does not pass validation at Smart Send. This means that some data is incorrect, and need to be fixed before making a new API call.

Typically this error is followed with details about what field(s) failed validation and why they failed validation. Fix the field mentioned and try to create a new label.