Form of payment in taxis

All taxis are required to accept cards but confirm with driver that their machine is “working”

You might consider using a taxi app. You order the taxi and pay on the app. Most drivers are honest, but using the app avoids any potential misunderstandings. Do realize the meter starts when the taxi accepts the fare (not when they pick you up). Two apps commonly used in Florence (and Rome) are itTaxi and FreeNow.

AppTaxi works in Florence as well and you can pay through the app. I've had good luck with it in northern Italy. Only call taxis to you or pick them up at taxi stands but do not try to flag them down or accept any "helpful" offers of taxis.

As people have mentioned taxis are required to accept cards as well as cash. You can confirm that the "machine is working" and that a card is okay before setting off if there is any doubt. Some people also make a point of asking for a receipt when you start out because the taxi drivers number is on the receipt so you know who they are. I haven't done this but some people think it reduces the possibility for hijinks since it makes you seem like a seasoned business traveller as well.

All that being said I have not had a problem with unscrupulous taxis since payment involved the lira so I just take taxis when needed and don't worry about it.

Have a great trip,
=Tod