Can 4G calling be used on devices that were not bought from 02?

[OfflineBloke]

I have replaced a Samsung Tab Active 2 (which O2 told me was not capable of making 4G calls) with a Tab Active 3 (Which the O2 IMEI check said was compatible.)
However, it now appears that not only can I still not make 4G calls (the option does not show up in Settings>Mobile Networks>Network modes), reading around on here it seems that only devices with pre-installed O2 firmware can be used for 4G calling.

Is it really the case that I have to buy  a device from O2 to be able to use the network for 4G calls? A sim only package can't be used with an unlocked device?

Thanks for any help, this whole thing seems to be just a scam.

[OfflineBloke]

So, a month on, the Tab Active 3 that I bought failed and I sent it back. I have wasted huge amounts of time trying to find other devices to replace it with and have been using the Tab Active 2 again. Having seen an instruction on another network advice page I checked their instructions. Looking under "SIM card status" (buried in network settings)  I see that Mobile voice network type is listed as LTE. Which would suggest that the older model that O2 say won't make Voice over LTE calls actually is doing.  The whole exercise has been an utter shambles, principally because O2 and Samsung don't know their own products and systems and have dismal customer service. "Just buy a new one" is their standard response. Shocking. Finding out whether something works (or will work) on a network really shouldn't be this difficult. I suppose I now just hold on and if I can still make calls at Christmas I will finally have confirmation that the older device worked all along.
Principle finding: O2 and Samsung can not provide reliable definitive information on product compatibility.

 

[OfflineBloke]

Not helpful.

[MI5]

@OfflineBloke 

O2 will say it's incompatible per say because tablets should only use data only sims which historically couldn't make calls.

With the advent of 4g calling, it may now be possible, but it won't have been tested by O2 and there will be no support offered for it.

VOIP calls via the likes of Whatsapp etc will be and have always been possible.