When you update your Stamps.com account password on the Stamps.com side, you’ll need to update the password on the ShipStation side as well. Otherwise, you’ll see an error like this below when getting a rate.
Head to your Account Settings (the gear icon in the upper right).
Next, select Shipping and then Carriers & Fulfillment from the sidebar on the left.
Once there, click Edit for the Stamps.com account that needs to be updated.
In this new window, click Reauthorize.
Here, enter your updated Stamps.com password.
Once you click Confirm, you’ll be able to start shipping with Stamps.com again!