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How To Refresh Merchant & Payment Tokens for USPS API

This article reviews USPS API tokens and how to refresh them

What Is a Payment Token?

A payment token is a temporary authorization issued by USPS that allows your system to process postage payments through the USPS API. It verifies that your EPS (Enterprise Payment System) account and chosen payment method (ACH or credit card) are valid and have sufficient funds. Payment tokens expire frequently (often every few hours) and are automatically refreshed as you rate or ship packages.

What Is a Merchant Token?

A merchant token is a longer-lasting credential that links your shipping software to your USPS account. It confirms that your system is authorized to access USPS services on your behalf. Merchant tokens typically expire every 7 days, but will automatically renew as long as USPS API interactions continue. When the merchant token expires, you may be prompted to re-authorize your USPS account through a USPS login page.

Troubleshooting Token Refresh Issues:

A payment token is set to expire in 8 hours. This is a restriction set by USPS. If you encounter this error—most commonly at the beginning of your shipping day—it can usually be fixed by re-rating a shipment (see below).

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If this does not resolve the payment token issue, below is a step-by-step guide on how to manually refresh your payment token.

How To Update Payment Token

Reasons the payment token may not refresh automatically:

  • Insufficient funds on your payment method (ACH or Credit Card)

  • Balance due

These can be verified on USPS’s EPS page. If there is a balance due or any warning of a past-due amount, this must be resolved by visiting your nearest post office location ( here) with your CRID, EPS account number, and the owed balance. Please note that you may be required to pay the remaining balance by check.

Finally, the payment method could be suspended or the credit card on file may have expired, causing a negative balance. It is recommended that two payment methods be on file (such as two credit cards, or one ACH and one credit card). This ensures that if one method fails, the other can be used and shipping will remain uninterrupted.

If this does not resolve your issue, you may need to refresh your merchant token. These tokens typically expire every 7 days, but they will automatically refresh as long as you are actively shipping.

Please note: The re-authorization process will time out if it takes too long, and the update may not be successful.

Before starting the refresh process, make sure you have your USPS.com login credentials handy, or that you’re already signed in to USPS.com in another browser tab. During the re-authorization, you’ll be redirected to the USPS website to verify your account. If you’re already logged in, you won’t need to enter your credentials again.

 

How To Update Merchant Token

If you have any questions or concerns, please don’t hesitate to reach out to our support team via phone, email, or chat.

ShipWise Support