ELEX Stamps.com Plugin – Authentication Failed Error


I am using the stamps.com plugin with WooCommerce in WordPress. It is installed correctly, but when I go to calculate shipping I get the following error:
Stamps.com – Unable to Get Auth: Authentication failed.

I am pretty sure I have the correct UN and PW because I can use it actually to get into my stamps.com acct.

Please help.


If the authentication information like UserID or Password is not correct, you get this Auth: Authentication failed error.

We request you to check the UserID and Password once again. For more information on troubleshooting, please refer the Stamps.com troubleshooting article.

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    • ELEXtensions
      Hello Johaluna, Please let us know the exact error you are facing. If you are using test mode, note that your web server IP should be whitelisted by requesting to Stamps.com. You can easily get it done by contacting stamps support. If you still face the issue, please raise a ticket and our technical team will help you out. Link to open a support ticket -> https://support.elextensions.com/
  1. bulwarkshieldus
    Hi I have the same problem and I am putting the correct credentials I try to create a support ticket but it does not leave me your page I need urgent help please.
    • ELEXtensions
      Authentication error appears because of two reasons: 1) If the username and password entered for Stamps are invalid.2) Or if you are using the stamps credentials in the wrong API mode. Please find the below troubleshooting document URL for our stamps plugin - https://elextensions.com/knowledge-base/troubleshooting-elex-woocommerce-stamps-com-plugin/ Hope you have received the support for the ticket you have raised with us. Thanks

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