[BattleFlag]

I was thinking mainly of self service fuel pumps. Often I choose to just fuel up and not go inside the store. It seems if “credit” is selected you are prompted to enter a zip code. I have never tried entering a bogus one so I don’t know if it would deny the transaction or not.

[katana]

I made an error once typing my zip code into a gas pump keyboard after sliding my credit card. It refused to operate. The idea is it prevents people from using a stolen credit card. Thieves are not likely to know the zip code of the person from whom they just lifted the card and one of the first places such people go and use the card are filling stations.

[sarasmom]

Yes, it would indeed be denied if you entered the wrong zip code at the pump using a CC.

(happened to me a few times)

[Rio]

I have experienced that, too at fuel pumps. I will try entering a bad ZIP to see if it has an effect.