[bombcar]

Some banks have their debit and credit cards almost identical.

You may have multiple cards from the same bank (personal, family, business).

Different cash back from the same bank making you want to use one card over another.

[robocat]

My bank does a slightly different cutout notch at the top of the card for credit card versus debit card. It is useful for orienting card when inserting into card readers (or cash machines).

Apparently an accessibility thing and maybe a wider standard than Mastercard. See image of cards near top of https://www.mastercard.com.au/en-au/personal/find-a-card/tou...