Update USPS Postage Account Billing Details | How To – ShippingEasy Knowledge Base

ShippingEasy processes all USPS postage purchases through Stamps.com. It is easy to update your Stamps.com account to add a new credit card or change your billing address.

Click the POSTAGE AND CARRIERS link in the top right corner of your ShippingEasy account.
Locate your Stamps.com Account Number and Password within ShippingEasy, on the POSTAGE AND CARRIERS page.
1. Your Account Number will be readily visible to the right of the Stamps logo. Click the blue text Show Passwords.
2. View and copy your Stamps.com Username and Password.
  
  For detailed instructions for finding your Stamps.com account information, view our step by step guide.
Go to the https://www.stamps.com/login.
Log in with your Account Number and Password.
On the upper left corner, click on your account number and then select Manage Account.
Then, on the right, click Account Settings and select Payment Settings:
Review your Payment Addresses. Click edit to make any updates necessary.