What do I need to watch out for when buying an unlocked phone on the used market?
I want my next phone to be "unlocked" so I can use it w/ any carrier - Verizon, AT&T, T-Mobile, Mint, etc. I'm based in the US, but if I travel internationally, it would be nice to be able to just pop in a local SIM card and continue using my phone like normal.
What gives me pause is, I see used phones listed as "US Version," and reviewers claiming the phone was not unlocked (for example, this Pixel 7a on Amazon).
Questions:
What am I missing here? Do these reviewers just not know what they're doing, or are they buying from shady resellers?
Does "US Version" imply I would not be able to use the phone internationally by just popping in a local SIM card?
Verizon deliberately conflates the term unlocked to mean not locked to a carrier (can use a non-Verizon SIM) instead of the bootloader being unlocked (can install a custom OS ROM such as GrapheneOS or LineageOS).
Their "unlocked" phones are all locked, so if you want a new OS that doesn't have their closed-source spyware then F you for buying the Verizon version
Verizon deliberately conflates the term unlocked to mean not locked to a carrier (can use a non-Verizon SIM)
This is what "unlocked" usually means to the general population though. If you search your favourite search engine for "how to unlock phone", most (if not all) results will be either about carrier locks or about getting into the phone if you forget your PIN/password.
Someone knowledgeable enough to even know about the bootloader would usually explicitly say "unlocked bootloader" to avoid the ambiguity.
I wanna run GrapheneOS, so thanks for the heads up.
Based on reviews, the listing in my OP looks like a mixed bag—some reviewers complaining that the boot loader is locked (hence they cannot flash a custom ROM onto it), others complaining that it’s unlocked (hence a security risk)—so if I get this phone, I guess it’s up to chance whether the bootloader is locked or not. 🤞🏻
Unique to the Pixel line, you actually can re-lock the bootloader. So if you can manage ADB fastboot (that is, follow the install process) then I wouldn't worry about the security risk in this case.
The GrapheneOS installation process is exceptionally easy to follow. It's much faster and easier than the old Cyanogenmod days
The specific variant is usually listed by the seller. On Amazon if you're buying it used I believe it would be listed near the condition information from the specific merchant.
You may also be able to message them to ask. The model number is printed on the outside of the original box, and is also available in the About Phone settings page, so it should be easy for the seller to find it.
The model number to avoid is G0DZQ.
GWKK I think is the ideal version, especially if you're traveling overseas. This is the global version so it should have the most radio bands available.
GWKK3 (AT&T version) should work great in the US on a non-Verizon network.
I have the G82U8 version, which apparently was originally for the Japanese market, but it works great for me in the US. I'm using Mint Mobile with GrapheneOS.
GrapheneOS developer is very toxic, if you trust him is up to you. I prefer not running his code on my personal devices, especially after him blaming large parts of his community for coordinated harassment. Watch Louis Rossman's video on it.
Although for security-focussed custom roms on the google pixel, like Calyx or Divest, you can re-lock the bootloader, so there's less security risk. A factory reset is required to unlock it again, similar to a factory bootloader lock.
Even if you don't have a Verizon version initially, when you switch over to them as a carrier, they may push an update to your phone thatt locks the owner out of a bunch of features.
I discovered this when my unlocked Galaxy S8 was moved fron Consumer Cellular to Verizon. -It sucks that after 20+ years they still have better coverage.
Look up the exact model of the phone then check GSMArena or a similar site to see which bands it supports - then check to see which bands your carrier requires.
Also, in the US I usually recommend eBay or swappa for phones - their buyer protections are robust and it's almost trivial to return the phone if there's an issue that isn't disclosed in the sale listing. Buying used/refurbed things on Amazon is a crapshoot in my experience.
Is this thing with unsupported bands ever an issue outside USA? It isn't a problem I've ever encountered in using any phone abroad or heard people of any other could try talk about.
The US is fucking weird. I'd honestly suggest you just buy a ready-out-of-box phone from the EU. EU laws make the device a whole lot more functional than what you'll get in the US.
If you travel to the EU it's easiest just to buy it in person over here - there are plenty of retailers that'll just sell you a new phone in box same day.
You certainly can if you'd like, you won't get a full refund of the value you spent. I ended up just buying my phone in the EU and bringing it back to Canada with me. An EU phone can run a US or Canadian SIM without issue - the problem only happens in the other direction.
So, like, my suggestion is just buy your phone in the EU then it'll work everywhere with any SIM.
I’m not an expert but my guess is this is more of a signal band issue rather a carrier-lock issue if it’s truly unlocked. Some phones only support specific bands that won’t work with certain carriers. That’s just my guess though.