Not necessarily - some carriers still lock the phone to the network even though you have apid for it. Best advice is to find out before you buy if this is something that's important to you.
Once your device is paid off, you can simply request an unlock code from your carrier. The legally have to give it to you.
- Postpaid Unlocking Policy. Carriers, upon request, will unlock mobile wireless devices or provide the necessary information to unlock their devices, for customers and former customers in good standing and individual owners of eligible devices after the fulfillment of the applicable postpaid service contract, device financing plan or payment of an applicable early termination fee.
- Prepaid Unlocking Policy. Carriers, upon request, will unlock mobile wireless devices no later than one year after initial activation, consistent with reasonable time, payment, or usage requirements.
For all the legal info regarding unlocking your phone, click here to navigate to the FCC website