The USPS testing environment will not work for most API users at this time. If you are having issues with getting shipping rates and you have completed the following steps:
- Filled in weights for all products
- Selected a USPS in shipping
- Filled in the API key
- Filled in the Base City (with just a City name, don’t do [city], [state] – that never works!
- Filled in the Base Zip Code (With just the simple zip code, 28360 not 28350-8502 !