Originally Posted by
architect1337
I did use a gas station before but got stumped on the zip code bit. Went inside with cash to pre-pay
You only need the zip code at the pump. You don't need the zip code if paying by credit card with the human attendant inside. (With the attendant, you tend to provide other verification, such as showing picture ID. Zip code is used at the pump because the pump cannot check picture ID!
)
I had the same situation in Europe (as a USA-based traveler) many times: Gas pumps kiosks wouldn't accept my swipe-only card, but the attendant inside the station would (at least at many stations).
As someone with a card from overseas, you shouldn't have to pay cash at most gas stations in the USA, but you may have to go inside to pay with a credit card.
(Having said that: In some parts of the USA, you'll find some gas stations that charge more for paying with a credit card than for paying with cash. So in
those cases, you may want to pay cash perhaps. Or else move on until you find a station that doesn't charge more for paying with a credit card...)