If "someone else" is referring to the cashier, the customer uses the payment machine themselves. In PIN using countries the waiter brings a machine or you step

If "someone else" is referring to the cashier, the customer uses the payment machine themselves. In PIN using countries the waiter brings a machine or you step over to the front counter. If someone else is your spouse, kid, or personal assistant; you tell them the PIN or ask the issuer for an authorized user card.