I always swipe asap, cashier can do whatever they need to do (usually 50000 ($500.00) debit) after the swipe is registered, while I'm entering pin, or even after pin is entered. If it's a new cashier, I swipe immediately when the total shows up and say "I need only 500 dollars on this debit" Sometimes the complain that they need to enter it first. Politely tell them that you've done it before and it doesn't work if they enter it before you swipe. Each card gets done the same way. Swipe before cashier hits the debit button. Some of my better cashiers immediately type 50000 and wait til I finish pin, then hit debit. The only thing that never works is if they do 50000 debit before you swipe the card.