After a tasty meal in Hong Kong, the server brings the credit card machine over. It seems friendly, the screen asks if you would like to pay in the local currency or US Dollars. Don’t be fooled! The payment processor is offering to convert the transactions for 3%-5% and they don’t have to disclose that. If you have a credit card with 0% foreign transaction fees, this negates that benefit. It’s also likely that your bank will charge a lower conversion fee than the processor (Schwab charges 0%). Always pay in the local currency.