2 years ago we went to Italy..had t-mobile download something on my phone and they said I would be able to use it there..could not even get a dial tone..do I need to get a sim card when I get there???
For about 30 euro you can buy a phone in Italy (TIM or Vodafone), and buy additional minutes. I used one for 10 weeks and it only cost about 50 euro total (I confirmed reservations every few days).
Don't know your carrier, however, my son was just in Italy with an Verizon IPhone 4S and it worked seamlessly after the simm was activated; I have a 20E phone that I "top up" when in the EU for calls.
Karen, a U.S. T-Mobile phone account should work in Italy. It is very expensive, though ($1.29 a minute for calls). It sounds like your phone did not have the correct frequencies for use in Europe, however. In the U.S., we use 850 and 1900 mHz. In Europe they use 900 and 1800 mHz.* Most newer phones (especially smartphones) have these frequencies. Older flip and candy bar style phones might not. What is the brand and type of phone that you have? I don't know of anything T-Mobile would have to download for your phone to work. They have to set their computers so your account will work for international roaming, but it has nothing to do with your phone. (You are a contract customer, right? T-Mobile prepaid won't work in Europe.) If your account is set for international roaming, you can remove the SIM card from inside your phone and put it in another "unlocked" phone with the correct frequencies (which you can buy for little over there). Or you can just use a phone and prepaid account you buy there. I suspect you'll have further questions, so post again or send me a private message and I'll try to help. *(Note, this is a simplification. With 3G and 4G, other frequencies are now being used in both places. But for calling, the simplified statement is still true.)
After we were assured by two different ATT staff people that our cell phone would work in Italy, it didn't. Further complication was that the landlady of our apartment put the cell phone prefix on the number we had to call, so the public phone didn't work either! Fortunately, the person at the Tourist Information Center at the train station just crossed out the two numbers and eased our panic.