Carrier-calculated rates are highly effective for obtaining accurate rates at checkout without the need to configure a Rate Card or complex rates based on zone, weight slab, etc. However, the initial setup requires assistance.
Below are a few possibilities to consider if it doesn’t work. You may reach out to Shopify support for help:
The address may be incorrect. The postal code must be a 5-digit postcode. A flat rate does not require a complete address to be valid, but live rates do.
The address could be in a location where USPS does not operate.
The services that have been enabled may not be suitable for shipping the specific item. For example, the weight limit for USPS First-Class Mail packages is 15.99 ounces (or just under 1 pound) for commercial rates and 13 ounces for retail rates.
You may also verify the exact ‘from’, ‘to’, and package details on the USPS website to check serviceability.
Also tried a few address from google that are companies. I tried a few address from the auto complete, and a few other I had in my DB. If it really is an address issue, can someone supply an d address that works as a test? I have no faith that that is the issue but want to rule it out.
If those are al that can make it fail it must be “The services that have been enabled may not be suitable for shipping the specific item.” but I do not see anything in the item that would not make it ship-able.
There is also a address under the business setup but that is not the one to use. I found this by clicking local delivery, it told me I had no location set up. Please add this to the troubleshooting steps!