Unable to unlock phone

[Centauri]

I am an over-25-year-old Verizon customer.

I have an old Samsung Galaxy S5 model SM-G900V phone I paid for long ago. I am trying to use it with a different provider outside the USA.  I purchased a SIM card and after inserting it into my phone  I am getting an error message:

"SIM card is not from Verizon Wireless".

This phone should have been unlocked a long time ago. After 3 long and grueling sessions with Verizon tech support, trying to explain what my problem is. I was finally informed that this phone could not be unlocked, since it is an old cell phone with technology that does not allow unlocking.

I find this hard to believe and I am now looking for somebody who can either deny or accept this statement.

I found many sites and apps that claim to unlock any phone for the price but I am reluctant to use the services since they could be bogus.  Besides, why should I pay for the service that should be performed for free? ATT has an Internet-based service to do just that: https://www.att.com/deviceunlock/ 

I will also be grateful for any opinions regarding the above-mentioned services.

 Thanks

[Ann154]

That phone model was a CDMA phone with GSM international bands. It might have able to be unlocked for international use at one time, but I'm not sure if it could be now especially if those same frequencies have been changed to LTE or 5G bands and might not work for 3g or 2g GSM. 

[Centauri]

Thank you very much for your response.

I do not pretend I understand everything, but this phone is 4G. I am not sure but according to the FCC regulations, this phone should be already unlocked. 

What about all services that claim that they can unlock any phone?

[SynthpopAddict]

With this phone being so old, it predates the current Verizon unlocking policy and with Verizon updating their infrastructure, may no longer be able to be unlocked since the system would no longer recognize a 2G or 3G phone.

I would not trust any 3rd party site claiming to be able to unlock any device.  If you have a streaming service offering the documentary series Underworld Inc., they had one episode featuring what crooks used to do with stolen cell phones.  It's truly frightening (and makes me hope nobody still uses an iPhone 6).

[Centauri]

Thank you very much. As I mentioned in my last post I do not pretend to understand everything. Could you please elaborate briefly on 2G and 3G mentioned in your post? 

The phone I am referring to is 4G.

Thank you for your time.

[SynthpopAddict]

You're welcome.  The "G" in cell phone terminology refers to the generation of wireless tech used.  Mobile phones started with 1G back in the 90s and now we're using 4G or 5G in the US.  With each new generation of technology, more functionality has been added.  First we got basic texting (SMS), then we were able to surf the internet, now we can use smartphones like desktop or laptop computers, because a high-end smartphone is a miniaturized computer.  The earlier generations of wireless tech (1G, 2G, and 3G) have been retired in the US, but 2G and 3G are still used in some parts of the world.

I looked up the specs for your S5 elsewhere, and you're correct, it does support 4G LTE as that was very new back in the day when the S5 was released.  It also supports the older 2G and 3G tech.  However, as to why Verizon refuses to unlock your phone, I have seen other threads in the forums where either there was some glitch in the system preventing the unlock, or the phone was purchased outside of Verizon and Verizon can't verify that you are the rightful owner of the phone since the purchase was not linked to your Verizon account.

If you have plenty of proof that the phone is legitimately yours, would try contacting the FCC regarding the persistent locked status.  Again, I do not recommend using some 3rd party source claiming to be able to unlock any phones.  Those sound like shady outfits who may not be able to do it, or will ruin something else in the phone, never mind that you're giving away your bank account details to shady folks.

[Centauri]

Thank you again, I think contacting FSS is a piece of good advice and I will follow it. My phone was purchased from Verizon and I do not see why it should be locked.  I will try to retrieve the purchase details.

Also thank you for the detailed explanation of terminology.