To give a simplified view of the way things work here In the UK... there are Pay as You Go (PAYG), Contract, and SIM-only offerings.
With PAYG, you pay up front for airtime credit. You may buy a PAYG handset, which will usually be locked to a network.
Contracts generally last for 24 months and you get a free or discounted handset, usually locked to the networks.
SIM-only deals are like contracts, except you don't get a handset; there are monthly contracts, or 12-monthly versions available.
We are allowed to unlock our handsets; those bought from Carphone Warehouse are all unlocked, as are handsets sold by Three. Providers will supply an unlocking code, sometime free of charge, but often not until a minimum period has elapsed.
How does it work in the US?
With PAYG, you pay up front for airtime credit. You may buy a PAYG handset, which will usually be locked to a network.
Contracts generally last for 24 months and you get a free or discounted handset, usually locked to the networks.
SIM-only deals are like contracts, except you don't get a handset; there are monthly contracts, or 12-monthly versions available.
We are allowed to unlock our handsets; those bought from Carphone Warehouse are all unlocked, as are handsets sold by Three. Providers will supply an unlocking code, sometime free of charge, but often not until a minimum period has elapsed.
How does it work in the US?