Open the Applied Payments button in the invoice in SuccessWare21 and look for the Authorizations. A credit card payment that was successfully charged using Mobile Technician will have both a Payment Pre-Authorization and a Payment Authorization filled in.
Note: These authorization numbers are sent over from SWRemote when the technician closes the job. If the job is still open on the device, these authorizations will not be filled in.
In the screenshot below, you can see credit card information attached to the invoice receipt: