Two ways to take card
Link a Stripe Terminal reader (UK): staff tap Card reader on the till, the amount appears on the reader, and the guest taps their card or phone. The sale is marked paid when the payment goes through, with no re-keying and no mismatch at the end of the night.
Keep your own card machine: take the payment on your machine as you do today and tap Card on the till, so it counts in your takings and cash-up. This suits venues tied into a bank machine or a contract they want to see out.