Tickets and passes for riding the Florence Métro, bus, and tram public transit system
A regular bus ticket in Florence costs €1.50 ($2) and is valid for 90 minutes once you validate it. You validate it by stamping one end in the machine on the first bus you board. You are allowed unlimited transfers within the 90 minutes, but must stamp the other end of the ticket when you board the final bus.
You can buy bus tickets at most newsstands and tabacchi (tobacconists)—which means any shop (often including bars and cafes) marked by a sign with a white "T" on a brown background.
There are also ticket machines placed near 500 parking kiosk/meters around Florence. These tickets are validated the moment you buy them (no need to stamp on the bus), and remain valid for 80 minutes from the time you purchase them.
If you wait to buy a ticket on board the bus (there's a machine on board), it costs €2.50 ($3).