Increasingly, buses and metros accept open-loop contactless from bank cards and mobile wallets. Check whether tapping out is required to calculate distance-based fares. Some cities cap daily spending automatically, making casual exploration affordable. Where acceptance is partial or absent, buy a reloadable local card. Store a backup payment method, and test a small trip first so you understand gates, beeps, and screen messages before the crowds grow.
When time in port is brief, compare two or three single rides with a 24-hour pass cost. If you plan a round-trip plus a mid-day hop, the pass may win, especially with included trams or ferries. Consider family or group options and zone boundaries. Don’t forget walking: if major sights cluster within a pleasant stroll, one paid ride each way can beat unlimited travel you won’t fully use.
In many European cities, paper or QR tickets require validation before boarding or immediately after. Look for small yellow or green machines near doors or at station entrances. Inspectors may appear without warning, and fines can be steep even for tourists. Keep your validated ticket accessible, note the time window printed, and confirm whether transfers are permitted. When in doubt, politely ask a driver or attendant to demonstrate.