To give you a straight answer, Jeliz is partially right. Depending on your rate plan, a full upgrade is available after 13 months on plans largeer than $75, and about 20 months on those smaller. In both cases, you cannot have more than 3 suspensions for non-payment during that time. An early upgrade is more expensive, and is usually available after 6 months.If you are getting a smartphone (Iphone, Android, etc.) the early upgrade price is $250 more than the regular price of the phone. For instance, an iPhone 3GS is usually $49, but on an early upgrade is $299. T regular phone is $75 more than the regular upgrade price. Again, for instance a phone that would normally be $100 less a $50 rebate on regular upgrade will be $175 less the $50 rebate.

Hope that helps.

PS. You cannot do 2 early upgrades in a row. If you did the first upgrade on an early upgrade, you will need to wait the full time (12-20 months) to do a second upgrade.