Where do I send Mastercard credit card payments? The mailing address is: P.O. Box 2711, Omaha, NE 68103-2711 Additionally, following the conversion, you will be able to make your payment through a transfer in Online Account Access or at any 3Rivers branch. Have more questions? Submit a request 0 Comments Article is closed for comments. Related articles What features does the mobile banking app offer? Mailing Address What is 3Rivers routing number? When are the funds available for me to use?