Wifi Calling

[Sinkers]

Hi,

I am thinking about purchasing a used Galaxy S9 plus.

Having poor reception at home, I need to have wifi calling working.

I had to replace my previous (unlocked from Vodafone) Galaxy S7 Edge and had to get an O2 Galaxy S7 Edge to get wifi calling working.

Have things changed, or will I need an O2 version of the Galaxy S9 Plus to get wifi calling working or would any unlocked S9 Plus work?

Thanks

[Cleoriff]

Hi @Sinkers 

To get 4G and WiFi calling your phone should be running O2 firmware. So if you buy from O2 you will be fine.

Info in this link

https://www.o2.co.uk/business/support/network-support/wifi-and-4g-calling#Samsung-set-up

[Sinkers]

Thanks for your quick reply.

I guess my question really is, can I buy a 2nd hand non O2 phone (unlocked) and will that work with wifi calling, or does it need to have the original O2 firmware on it. Indeed can one flash O2 firmware onto a non O2 phone to make it compatible with wifi calling with O2?

Regards

[Cleoriff]

@Sinkers 

A second hand non O2 phone won't work with wifi calling.

With regards flashing to get the right firmware, that has been hit and miss from what I've read.

ie it SHOULD work but some people have had issues.

[Sinkers]

Many thanks for that

[MI5 · Accepted solution]

@Sinkers wifi calling will work on any S9 regardless of firmware.

[Cleoriff]

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@MI5 wrote:

@Sinkers wifi calling will work on any S9 regardless of firmware.

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Well if that's the case, that's a mistake on my part. I've read a few posts on here before I answered which claimed it didn't.

[MI5]

Everything from S8 onward works on any firmware (allegedly).

[Cleoriff]

In fact, in the link I gave it states this

Your device should use O2 firmware if you bought it direct from us in an O2 shop, online or over the phone.

To check if your phone’s running O2 firmware, dial *#1234# and look at the CSC entry. If this line includes ‘TEF’, ‘O2U’ or ‘OTF’ then your device has O2 firmware and you can set up Wifi and 4G Calling. 
If the CSC doesn't include one of these codes then Wifi and 4G Calling isn’t supported on your phone right now.

If you need more info contact O2 business customer services.

[Sinkers]

>wifi calling will work on any S9 regardless of firmware.

That is very interesting - and good news. Thanks