If you live in an area that's covered by AT&T's network (which is most places these days), Cricket Wireless is one of your best bets for an MVNO that's powered by the network but features considerably lower rates compared to going through AT&T directly.
Cricket's selection of phones has gotten rather good lately, but you still won't find nearly as many devices compared to what's offered to AT&T customers. Whether you already own an AT&T phone or want to purchase one to use on Cricket, doing so is actually pretty simple.
Confirm that you have an eligible device
Since both AT&T and Cricket use GSM bands, bringing phones from the former over to the latter is a piece of cake. Any AT&T phone that's not currently active on the carrier and has been unlocked for use outside of it should work on Cricket without a hitch, but just to confirm that everything is hunky-dory, you can use Cricket's online tool that lets you punch in your phone's IMEI number to see whether or not it's compatible.
Buy a Cricket SIM card
After confirming that you have an eligible device, your next step for using an AT&T phone on Cricket will be to purchase a SIM card. You can buy a SIM card either from Cricket's website or Best Buy, and it'll typically set you back $10 when it's not being discounted or given away for free.
Cricket's Universal SIM Card Kit is the only one that's sold, and what's great about it is that it can be adjusted to fit phones that use Standard, Micro, and Nano SIM slots.
Activate the SIM card and add service to it
Once you've got your Cricket SIM, you'll need to activate it. If you purchased the SIM on Cricket's website, you'll fill out your order and phone number on the site and then click the activate button. Put the SIM card into your AT&T phone, power it on, and you'll be good to go!
If you bought the SIM card somewhere else, you'll first go to Cricket's website and enter in your ICCID and IMEI numbers. From here you'll select which plans and features you'd like to use, checkout, put the SIM card in your phone, power it on, and you're done.
