Visa has tweaked its chip debit card transaction-routing policies to help merchants and acquirers better understand implementation options pertaining to the adoption of EMV chip technology in the US.

The latest move follows new guidance from the Federal Reserve and address a Federal Trade Commission inquiry.

With Visa chip cards, debit routing and processing are enabled by two payment application identifiers (AIDs) on the chip – the US Common Debit AID or the Visa Debit AID.

An important modification by Visa enables merchants that they can use only the AIDs on a debit card’s EMV chip to route a point-of-sale transaction to the debit network of their choice.

The common AID supports not only the Visa and MasterCard networks, but also over a dozen PIN-debit networks.

Additionally, Visa has clarified that merchants can use the Common Debit AID exclusively to route US debit transactions, if they opt.

Furthermore, merchants are also not required to ask the cardholder to select the AID or network for processing debit transactions.