Best answer: If you want to keep your phone, it will need to be unlocked and compatible with a new carrier. To keep your number, you will need to port with the new carrier. Be sure not to cancel your old account until your port is complete.
- Manage your AT&T account: AT&T Wireless Support
- Manage your T-Mobile or Sprint account: T-Mobile Support
- Manage your Verizon account: Verizon Wireless Support
Which carrier should you switch to?
One of the main things to consider is the network. While all carriers have made huge strides in recent years to make sure they offer service where most Americans live, some rural areas still strongly favor one carrier over another. Check out the coverage maps for AT&T, T-Mobile, and Verizon to get an idea.
If you like the network but don't like the plans, it's time to check out an MVNO. The best MVNOs can save you money by getting rid of the features and services you don't need and offering a simplified phone plan. For example, if you know you need the Verizon or T-Mobile network, you can choose an MVNO based on Verizon or an MVNO on T-Mobile.
Unless you own money on it, you can probably bring your phone as well.
I want to keep my phone
Quite a few new phones are compatible with multiple carriers meaning that you are a SIM swap away from connecting to a new network. Once you check to see if your phone will be compatible with a new carrier, you will have to make sure the phone is fully paid off and unlocked. On some networks, you will need to know your account password or PIN to finish activation.
Check BYOD compatibility
The first thing to check is that your phone will work on your new network. While many phones now work with nearly every carrier, there are a few older models, especially those built for Verizon and Sprint, that won't work with other carriers. Be sure to check your phone with your preferred carrier, or you may be stuck trading in that phone and losing value. You will need your IMEI number to check your phone. This number can be found in the about section of your phone's setting or, more conveniently, displayed by typing *#06* into the dialer.
If you are ready for a new phone, there are many great unlocked phones you can get that will work on most carriers. All of the major carriers support bringing a 5G phone as well as long as you sign up for a plan that supports it, have a phone that's compatible with its 5G bands, and of course, you should make sure you have 5G coverage in your city.
On AT&T, most GSM unlocked phones will work with its 3G, 4G LTE, and 5G network with a simple SIM card swap. In this case, the SIM card should carry all of the information the phone needs to connect to AT&T's network. In some rare cases, you may need to manually enter the APN settings yourself. In most cases, this information will be filled automatically. You can check to make sure your phone is compatible by checking it on AT&T's BYOD page. 5G phones should work if they support band n5 but be sure to check with AT&T beforehand.
T-Mobile is largely the same process as AT&T with a GSM network that will work with most phones. With a SIM card swap, a compatible device should connect automatically though in rare cases, you may need to enter the APN settings manually. Check your phone on T-Mobile's BYOP page to be sure. T-Mobile uses the 5G bands n71 and n41 and will work with most 5G phones made for the US market. Be sure to check with T-Mobile anyway.
Sprint is no longer adding new customers to its network, and all Sprint-related services are being redirected to T-Mobile's network and plans. If you were thinking about buying a Sprint-branded device used or unlocked, be sure that it will work with T-Mobile's network instead.
Verizon's network may be a little pickier, but you can still check your phone on its BYOD page to see if it's compatible. If so, you will just need a SIM card from Verizon to get connected. Verizon does support unlocked 5G devices on its network as long as the phone supports its n5 DSS 5G bands. The easiest way to find out for sure is to check with Verizon.
If you are compatible, you just need to make sure you own the device.
Make sure you don't owe your current provider
While phone carriers no longer lock phones to one network like in years past, you still might not be able to take the phone with you. The first thing to check is that you are not leasing the phone or still making payments. If you are, you will need to buy out the phone to take it to another carrier. This shouldn't apply if you leased your phone through another store or the manufacturer.
To be sure, you can contact your current carrier to see if you own your device or if you have any outstanding fees that need to be settled.
- AT&T - (800) 331-0500 or 611 from your AT&T phone
- T-Mobile - (800) 937-8997 or 611 from your T-Mobile phone
- Verizon - (800) 922-0204 or 611 from your Verizon phone
- Sprint - (888) 211-4727 or 611 from your Sprint phone
If you want to get a new phone number, you can make a new account and get a SIM card from your new provider. You will still need to follow activation procedures on Sprint.
I want to keep my number
If you want to keep your number, you can port it to your new carrier. Do not cancel your old service until the port is complete.
Have your previous account information
You will need your old account information to complete your number transfer. You will need your current account number and password/PIN, as well as the account holder's name, billing address, and Social Security number. Your new provider will use this information to request your number to transfer.
You can check your number's port eligibility online.
If everything looks good, you'll complete the rest of the procedure with your new carrier. You may need to pay line or device activation fees when you start your new service.
Contact AT&T Support Contact T-Mobile Support Contact Verizon Support
Source: androidcentral