Just a warning for those switching carriers (In the USA at least). Carriers in the USA do not pro-rate your final bill. This may end up costing you over $200 if you port to new iPhone 5 with another carrier right after your new billing cycle starts. I got screwed over with Sprint a few years back when my new billing cycle started on the 24th and I started service on the 26th and Sprint never pro-rated. ATT, Verizon, T-mobile all do not pro-rate. It's ironic you pay pro-rated charges when you start but they won't pro rate when you terminate your contract. Yeah, there are some who may call and complain and sometimes you may get a willing rep who will refund you back the pro rated charges but it's getting more difficult.