If you’re living in the EU, using an EU phone contract, just be aware that the EU roaming allowance may be lower than your phone’s normal data plan.
If you’re flying into Rome Fiumicino Airport, and want to buy an Italian sim card before you leave the airport you’ll find sim card stores in the baggage collection area in Terminal 3, and the Terminal 3 Arrival Hall.
If you want to save time and avoid the hassle of buying the sim card in Italy you can rent an Italian pocket WiFi with unlimited data in Itay and the EU, for delivery to any address in Rome, Italy or another EU country – such as your home, hotel, a post office delivery point, etc.
As of October 2019, the tourist sim card is 20euros + 10 euro fee for the sim card, for a 30-day sim card plan that includes 200 minutes, 15GB 4G Data, and unlimited chat on apps such as Facebook Messenger and Whatsapp.