Network carriers and MVNOs will usually let you bring your own phone (they call it BYO) to their network.
There are no specific guarantees to BYO and most carriers will ask you to find your IMEI number of your existing phone before they will confirm that you can switch. The IMEI number is the unique code that relates to your exact phone type and the carrier that provided it.
Check which technology your own phone works on - there are two types - GSM and CDMA.
Don't worry, it sounds complicated but its pretty simple.
GSM phones will work on T-Mobile and AT&T networks as well as all the carriers that operate on those two networks.
CDMA phones work on Sprint and Verizon networks as well as all the carriers that operate on those networks.
Some new phones like the iPhone 6s will work on both networks as well as some of the newer Google Nexus phones.
Make sure that your'e phone is unlocked, you can ask you existing cellphone provider to do this. Usually you will have to have paid all of your monthly bills, be upto date on all your payments and have fully paid off any outstanding phone finance or phone installments.
Use our cellphone comparison search to find a carrier that works on the same network as your phone
Sprint - click here to find BYO carriers on the Sprint network
T-Mobile - click here to find BYO carriers on the T-Mobile network
AT&T- click here to find BYO carriers on the T-Mobile network
Verizon - click here to find BYO carriers on the T-Mobile network
Once youv'e selected a carrier to bring your phone to then its simple - click through from our site and buy online or in-store.
Don't cancel your current contract or plan yet, wait until you have received your new sim card, then port (switch your number) your number to the new carrier when you activate the sim card