Card schemes treat it as a separate terminal type, flagged in the authorization message. That flag changes the rules applied: which cardholder verification methods are allowed, what fraud liability applies and which merchant category codes can be used. Hardware is typically a reader module built into the host machine, combining contactless, chip and sometimes magnetic stripe, plus a PIN pad where required, all approved under PCI PTS POI.

Most follow one of three flows. Fixed-price flows, like a vending machine selling a EUR 2 drink, authorize the exact amount before the product is released. Variable-amount flows, like fuel or EV charging, authorize an estimated amount first, deliver the service, then capture the real amount and release the difference. Post-paid flows, like transit gates, tap at entry and aggregate taps into a later charge.

A driver at a fuel pump might see EUR 150 held on the card while buying EUR 60 of fuel. The terminal captures EUR 60, but the difference is released only when the issuer processes the completion or the hold expires, which can take days. Poorly integrated systems that never send the completion message leave cardholders complaining about money "taken twice" and generate avoidable disputes.

In the EEA, the SCA regulatory standards contain a specific exemption for unattended terminals used to pay transport fares and parking fees, so those payments can go through without PIN or biometrics. Other unattended payments follow the normal contactless and SCA limits, and some kiosks accept no-CVM transactions only below a low ceiling. Fraudsters target unattended terminals because there is no witness: card-testing and skimmers fitted to the reader are the main risks.

EV charging is the fastest-growing category. The EU Alternative Fuels Infrastructure Regulation (EU) 2023/1804 requires new publicly accessible chargers of 50 kW and above, installed from 13 April 2024, to accept ad hoc payment by card. That rule turned many charge-point operators into card-accepting merchants, needing an acquirer or a payment facilitator able to underwrite the risk of variable-amount card-present transactions with no staff on site.