The move is hoped to provide a better overall service
Isle of Man Bank and NatWest International are switching their debit cards from Visa to Mastercard.
All customers of both banks will receive new cards as they're rolled out.
They say they regularly review suppliers and are making the move because they think it'll allow them to provide a better overall service.
The new cards are said to be more sustainable and will have features to help customers with visual impairments.