Mellon uses key card schemes and cooperates with important local and international processors, among which:

MasterCard  |  www.mastercard.com
American Express  |  www.americanexpress.com
Diners Club  |  www.dinersclub.com
JCC (Κύπρος)  |   www.jcc.com.cy
Borica (Βουλγαρία)  |  www.borica.bg
First Data  |  www.firstdata.com
Euronet  |  www.euronetworldwide.com
CaSys (FYROM)  |  www.casys.com.mk
DinaCard (Σερβία)  |  www.dinacard.nbs.rs