Cognomen বাই (Paj 
, বাই 
) , all over the world, is quite a rare family name. The family name বাই is habitual in Croatia, where it is quite a rare surname, Slovenia, and Hungary, where it is a rare surname. Measured by absolute frequency, it is the most numerous in Bangladesh, India, and Indonesia. Much less frequently, বাই is the forename as well as the last name.