trophlin
Being that you're on T-Mobile they have run some killer deals on iPhones. You're X should get you a new iPhone for free. It does need to meet a few criteria:
1) Device turns on.
2) No screen damage.
3) No liquid damage. The LDI (liquid damage indicator) must be white.
4) Find my iPhone & anti-theft disabled.
 
For Mother's Day they accepted an iPhone 8 for a new iPhone 12 for free. The only thing is that you get paid back in monthly payments. I'm going to pay off the phone and get it unlocked after 40 days (has to be used on their network for this amount of time) since that's the time limit to unlock a T-Mobile locked phone.

kram36
This is the kind of question you ask BEFORE you by something.

StrawHatLevi
Make sure it's sim unlocked reset of course.

phantomshroom
Before buying ANY phone regardless of where you are purchasing it, you must check the IMEI # of the phone to ensure that it is not a lost/stolen phone.
 
Every phone on this planet has built in diagnostic chips to allow users/repair technicians to use various codes to test/display stuff.
On the keypad dial *#06# to see the 15 digit IMEI #. If it is all zeros or mostly zeros, or displays 'null/null' then you do NOT want to buy that phone. I have provided a few links to help you verify your current phone plus any future ones you intend on purchasing.
https://imeipro.info/
https://www.imei.info/
https://imeicheck.com/
 
Many thieves that steal phones bring them into shops to purchase a newer phone with discount because they hand over the stolen one to swap & get credit for it.
My girlfriend over the years has tried to buy phones online for herself & her son & I told the seller that I wanted the IMEI of the phone before we purchased it. Those that said OK, we bought after I checked the IMEI out. Those that refused, I reported them & their ad to the police & each & every one of them were arrested & charged with theft & done 2-5 years jail time. Phones without a valid IMEI have been tampered with (either by bad attempts at rooting the phone, or attempting to use custom roms & bricking their phones, etc.). Most mobility companies will NOT allow a fake/false/stolen IMEI on their network.
 

phantomshroom
Yes, they should but because they are not solely cell phone shops, they may overlook that check :o)
 
Cell phone stores that only deal in cell phones would not overlook that check. It was my cell shop that educated me on these facts many decades ago when I bought my first phone.
I am glad that everything checked out for you & you have a newer phone.