Chip and PIN systems can cause problems for travellers from countries that do not issue Chip and PIN cards as some retailers may refuse to accept their chipless cards. While most terminals still accept a magnetic strip card, and the major credit card brands require vendors to accept them, some staff may refuse to take the card, under the belief that they are held liable for any fraud if the card cannot verify a PIN. Non-chip-and-PIN cards may also not work in some unattended vending machines at, for example, train stations, or self-service check-out tills at supermarkets.