I finally got it to work, with a few changes to the payload. - orderStatus is not used - the NS RMA internalId needs to be sent as ReturnAuthorization>internalId - item level isClosed needs to be set to "true" Here is the working payload XML, in case this helps anyone in the future <ReturnAuthorization internalId="64924">…

Thanks for the response Robert. I got it to work, but I will keep your suggestion in mind for future reference. I will post the resolution separately. Regards, Joe