USPS can be enabled for domestic rates (United States shipments only).

If you will be shipping internationally, we recommended activating USPS with another carrier (UPS and/or FedEx). If you do not want to offer UPS and/or FedEx as your international rate(s) provider and prefer to use an International flat rate option, contact Site Store Pro support to enable this feature on your store. If you will not be shipping internationally, USPS can be used in by itself for domestic-only shipments.

If the USPS is enabled, the application will query the USPS domestic rate server with the total order weight and return the available rates based on the order’s shipping address or alternate shipping address distance from the shipping origin specified on the shipping configuration screen in the web-based admin.

Returned rates from USPS can be marked up to adjust from the returned rate(s) to the actual rate(s) that you will be paying to USPS to ship the package. (Mark up value is dollar-amount not percentage. Contact Site Store Pro support if you required % based markup.)

To use the USPS Domestic Rate Calculater API, you must register for USPS Web Tools account and get a USPS UserID number. Register for a USPS Web Tools Account here.

After you have received your USPS UserID, enter it in the USPS User ID field and check USPS “on” as a rate option on the shipping configuration page.

Note: You must use request USPS to set your account to their “Production Server” after receiving your UserID. By default, your Web Tools account will be set in test-mode and will not return all rate types.

Copy and paste the info below into an email and sent it to internetcustomercare@usps.gov with the subject line: WebTools Production Server Account Activation

Replace [Your USPS UserID] with your actual WebTools User ID before sending the email to USPS.

Please set my USPS WebTools account to Production Server Mode. Below is my account info:

- What API are you trying to access = Domestic Rates API (Rate Calculator)
- Are you using a third party shopping cart = Yes
- Name of shopping cart = Site Store Professional
- Web Tools username = [Your USPS User ID]

After you have entered your USPS UserID and received confirmation that your account is in ‘Production Mode’,  turn on USPS as a rate option and set it to LIVE mode on the shipping configuration page.

Finally, select the rate types you want to offer to your customers on by going to ‘Store Setup’ > ‘Shipping Setup’ > USPS Rates Configuration

Note: You cannot use flat-rate shipping options when using FedEx, UPS or USPS rates. You should uncheck all rate types and carriers that you are not using on the shipping configuration screen