The most common issues that can come up when registering your UPS account with us, are caused by the mismatch in the contact information. For more info on how to add the accurate contact details and where to find them, pelase check this article.
However, if you are receiving the following error: ‘Request cannot be processed, please contact UPS customer service at 1-888-851-4901’ this means there is a credit issue with your account and you will not be able to ship any packages via any applications that are using your UPS account. The best thing to do in this case is to simply give them a call at the number provided and they will further assist you.