It refers to the Tourist Tax introduced in 2012, according to which, all tourists must pay a small fee of around 1-2 euros (per adult, per night, up to seven overnight stays), with only a few exceptions. This fee is usually collected by the property owner or manager and is paid to the local commune. This fee is then invested in the improvement of tourism and the maintenance of the local infrastructure. Please be aware that the city tax is never paid in advance. So, even if you have paid for your rental villa in full already, you will still have to pay the city tax upon arrival to Tuscany (in most cases, in cash).