I have Verizon and I added that plan too. After I met with Lesley to get my rental car I had to contact the owner of the condo so that he could meet us there. The service worked great and it is valid for 24 hours from the time you first use it. I think my wife inadvertently responded to a facebook message and it started a second day. From that point we just left the phone in airport mode and if we needed to call someone we would just take it out of airplane mode. Luckily we didn't have to use it and just used the wi-fi. I didn't try to use the phone via the wi-fi connection but I read on a different post that you can. Actually we really just wanted to be unplugged.