[AC Question]

Time to get a new phone. Looking at either the S3 or S4, depending on how much I can spend. The question is, if I bought them as AT&T phones (apparently there's a difference in what each has and the AT&T one seems better) would I be able to convert them to Verizon if I needed to? I found info on Google saying it can go the other way around (from Verizon to AT&T) with a few steps, but nothing saying I can go from AT&T to Verizon.

Verizon used to be the best in my area when my family was trying out different providers before, but because it's been so long AT&T might be an option now. They say they service my area, but actually having working service is a whole different thing because my house and where I work are both very bad locations for service. My plan is to try out Straight Talk in this area using the AT&T SIM and if that doesn't work I need to be able to switch the phone to Verizon and do whatever flashing may be needed so I can go back to PagePlus. I've been stuck with PagePlus for a while now, but they don't offer 4G (which wouldn't be an issue if I got the S3) and they're currently quite a bit more expensive for the data I need.

[RumoredNow]

No. You can't go from AT&T branded phone onto Verizon.

AT&T is a GSM network and needs a SIM card. Verizon is CDMA network with no SIM needed. And they won't take anyone else's phones - no "unlocked" phones allowed on Verizon.

The reason you could use Verizon phone on AT&T is this; some Verizon phones do have a SIM slot for international travel. It only connects to the 2G and 3G radio... If you get the Verizon phone unlocked an AT&T SIM works, just not at full speed - no LTE for sure.

Best bet. Buy a phone branded to the network you are going to use - or get a factory unlocked phone (never branded to a carrier) for use with a SIM if you want to change networks later.

[cnotes2019]

No. You can't go from AT&T branded phone onto Verizon.

AT&T is a GSM network and needs a SIM card. Verizon is CDMA network with no SIM needed. And they won't take anyone else's phones - no "unlocked" phones allowed on Verizon.

The reason you could use Verizon phone on AT&T is this; some Verizon phones do have a SIM slot for international travel. It only connects to the 2G and 3G radio... If you get the Verizon phone unlocked an AT&T SIM works, just not at full speed - no LTE for sure.

Best bet. Buy a phone branded to the network you are going to use - or get a factory unlocked phone (never branded to a carrier) for use with a SIM if you want to change networks later.

Huh?? ..... Most if not all of Verizon's latest lte phones come sim unlocked. And Verizon's iphone 5c and 5s you get lte on AT&T and tmobile. And their phones share an lte band with I believe either tmo or AT&T.


Sent from my iPhone using Tapatalk

[ShadowGX]

OP here, didn't think I might have to respond so I didn't bother registering until now.

Not having Verizon 4G LTE won't be an issue. PagePlus doesn't support 4G currently, so if I had to switch it to Verizon there wouldn't be any difference there for me, I can't get 4G no matter what.

As for needing a SIM card, I have one for both AT&T and Verizon so that won't be an issue should it be needed. Back when I had my Droid Charge a SIM was required to use the 4G, so am I to assume something has been changed there or is there some confusion?

As for the "best bet" part... well, I don't KNOW which carrier I'm going to use until I try AT&T and see if it works. If it does, I'll use it. If not, I have to switch back to Verizon and I can't afford yet another phone just for a carrier switch.

While browsing eBay for prices there are unlocked variants, but I'm not really sure how that works. When I go to try out AT&T on will it lock to that carrier or something, and them I'm screwed with no way to change it back, or does it stay unlocked? I'm definitely no expert on this stuff and I've already screwed up with one phone, so I want to make darn sure this time.

[RumoredNow]

Huh?? ..... Most if not all of Verizon's latest lte phones come sim unlocked. And Verizon's iphone 5c and 5s you get lte on AT&T and tmobile. And their phones share an lte band with I believe either tmo or AT&T.

Well it's good if Verizon is loosening up a little. But does it mean you can use an unbranded or unlocked phone on Verizon? Not such a huge deal if they have their SIM unlocked for travel or jumping off their network if their 3G and EDGE are still CDMA that limits the rados on their branded phones. GSM LTE isn't everywhere quite yet.

iPhones are not the same as branded Android phones with specialized radios tuned to a specific carrier...

OP here, didn't think I might have to respond so I didn't bother registering until now.

Not having Verizon 4G LTE won't be an issue. PagePlus doesn't support 4G currently, so if I had to switch it to Verizon there wouldn't be any difference there for me, I can't get 4G no matter what.

As for needing a SIM card, I have one for both AT&T and Verizon so that won't be an issue should it be needed. Back when I had my Droid Charge a SIM was required to use the 4G, so am I to assume something has been changed there or is there some confusion?

As for the "best bet" part... well, I don't KNOW which carrier I'm going to use until I try AT&T and see if it works. If it does, I'll use it. If not, I have to switch back to Verizon and I can't afford yet another phone just for a carrier switch.

While browsing eBay for prices there are unlocked variants, but I'm not really sure how that works. When I go to try out AT&T on will it lock to that carrier or something, and them I'm screwed with no way to change it back, or does it stay unlocked? I'm definitely no expert on this stuff and I've already screwed up with one phone, so I want to make darn sure this time.

If you buy a GSM (only works with a SIM) phone that is unlocked either by the factory or afterwards... Using it on a network will NOT lock it again. Once unlocked, always unlocked.

[KristiinAZ]

Resurrecting this thread to present time.

I want to unlock an AT&T S4 to use on Verizon. I have a 4G LTE Sim card to use too. Will the phone work for me, after unlocked, to make and receive calls and texts?

[Rukbat]

No. An AT&T S4 has GSM radios. For Verizon you need CDMA radios (which the Verizon version of the S4 will have - and it won't work on AT&T). They're totally different technologies.