Can’t make heads or tails of this… Sometimes fails sometimes doesn’t, no documentation to understand what this error means- I’ve tried adding more address fields, less, validating address first, etc, but this still persists sporadically. Tried calling both wwwcie (test) and live versions of the API, no difference there.

Failure rate is like 1 in 10 requests (different origin, same destination).

Anyway, if anyone knows what NPCS even is, maybe that would help. Thanks!

Full error text:

{"response":{"errors":[{"code":"591","message":"Unable to find NPCS Response Error Codes"}]}}

Example request body:

{"originCountryCode":"US","originStateProvince":"TX","originCityName":"FORT WORTH","originTownName":"","originPostalCode":"76137-4010","destinationCountryCode":"US","destinationStateProvince":"CA","destinationCityName":"IRVINE","destinationTownName":"","destinationPostalCode":"92614","shipDate":"2024-08-03","numberOfPackages":"1","billType":"03"}