It's extremely rare, but it's possible that a phone listed as fully "unlocked" could arrive to you from a seller showing "No Service" when you try activating it on your carrier's network.
At Back Market, we work closely with our sellers to make sure that this doesn’t happen, but in the unlikely event that it does, here’s what to do.
Check that your phone really is unlocked
If you go to your carrier, and they tell you that your refurbished device is locked or even blocklisted, you can always double-check to make sure. There are several ways to check if your phone is really locked:
Replace the SIM card
A common solution is to turn off your phone, replace the current SIM card with another carrier's SIM card, and turn your phone back on. If you see a message on the screen asking you for a SIM unlock code, then the phone is locked.
Check your settings
Go to "Settings" > "Cellular" > "Cellular Data Options" > "Cellular Data Network". Some phones will display "Cellular Data Network" once you select "Cellular." If you don't see "Cellular Data Network", your phone is probably locked. Please note that this option isn't 100% foolproof — you may have an unlocked device but still not see "Cellular Data Network."
Go to "Settings" > "Connections" > "Mobile networks" > "Mobile operators" > "Search Now". If the search displays multiple networks, then your phone is most likely unlocked.
Check using your phone's IMEI number
To find your IMEI number, you can do the following:
Go to: "Settings" > "General" > "About" > "IMEI" (scroll down)
"Settings" > "About Device" > "Status" > "IMEI"
Alternatively, whether you're using an iPhone or Android, you can dial #06# on your keypad, press call, and your IMEI number should appear.
Once you have your IMEI number, you can go to an IMEI checker site where you input your IMEI number and see if your phone is unlocked or not.
See which wireless frequency standard the phone works with (GSM or CDMA)
Another possible reason for your issue could be that the phone doesn't work with the wireless standard your carrier uses. A phone may be unlocked and still not work with your carrier. To explain why we need to delve into some cellular tech history. US carriers have historically used two wireless frequency standards, GSM (Global System for Mobiles) and CDMA (Code Division Multiple Access) — you might know them better as 2G and 3G.
AT&T and T-Mobile have always used GSM, which is also the main standard used by most countries outside of the United States. Very few countries use CDMA, which was previously used by Verizon and Sprint.
If you happen to have an unlocked CDMA phone when you use a carrier that primarily uses GSM (or vice-versa) you may have connectivity issues. Before purchasing an unlocked phone, it’s wise to first check the specs to see which standard the phone works with and to know which wireless standards are used by your carrier.
Contact your carrier
Once you've verified that your phone is unlocked and/or runs on the correct frequency, you can go to your carrier, and they’ll help you transfer your account to your refurbished device. Check out this article with links to major carriers and MVNOs that operate in the US.
Contact us if your phone really is locked
If you've double-checked using one of the methods above, and it turns out that your phone really is locked, please reach out to us so we can help resolve this with the seller. Just log in to your Back Market account > "My orders" > "Ask for help". We'll do our best to respond within 1 business day.