Duality

In simple terms, duality refers to payment card issuers which participate in both of the two national bank card organizations, Visa and Mastercard.

Up until 1976, duality wasn’t an option. Card network policies limited issuing banks to either the Visa or Mastercard networks (known at the time as National BankAmericard and Interbank Card Association/Master Charge, respectively). In 1976, both associations – at the urging of the federal government – allowed financial institutions to issue both card brands, and banks quickly did so

Some industry experts feared the move would severely decrease competition between the two credit card giants and lead to a duopoly; some modern experts say this is exactly what happened. Today, the  top two credit card associations together control more than 75% of the credit-card market.

At the same time, the networks can be highly influenced by the large banks they serve. This has potentially stifled competition and locked Americans consumers into a payment system that has failed to keep up with modern spending habits.