What does "The Shippers shipper number cannot be used for the shipment" mean?
This error is unique to UPS, and there are two typical causes.
- Check that the from address matches the address you have set in your UPS account.
- Make sure that your Shipper Number is connected to your ups.com account. (See steps here)
- Log into your UPS account, or call your UPS rep and check that your account has not been suspended.