The "pound key" refers to the symbol .
The pound key on a debit card terminal is simply a functional tool. It acts as a "submit" button for the banking machine. Without it, the terminal wouldn't know when you had finished typing your PIN. So, the next time you tap that # button, you can think of it as hitting "Enter" on your computer—you are simply telling the bank that you are ready for your money to move. what is a pound key on a debit card