India, Feb. 25 -- Multiple users of forex cards issued by YES Bank in partnership with MakeMyTrip-owned startup BookMyForex alleged that their multi-currency cards saw unauthorised transactions. Many of these attempts failed due to insufficient balance on the cards, but some users alleged that they lost funds.

"My #bookmyforex card was used by someone in BRL for this grocery shop MIX MATEUS BAYEUX BR for around $350 USD with multiple transactions #yesbank. Some of the transactions failed but some succeeded, and I lost $350 USD," a user said on X.

Fearing a data breach, YES Bank has begun blocking cards in specific cohorts that may have been affected by the fraudulent transactions, sources told Inc42, adding that the financial impact was...