Can't text to +44 numbers

[Matty3uk]

I got a used Samsung Galaxy S5 a few days ago.
When I send a text with a number starting 07 it sends with no problem.
But as soon as I get a reply the number changes to the +44 format and I can't reply.
It fails every time until I delete messages go to my contacts and select text message from there so the number start with 07.
My internet works fine.
I've setup the APN as on plusnet's website.

Please can someone help me

 

[Matty3uk]

can anyone help

 

[ironass]

Two things...

1. Never publish your phone's IMEI number on a forum.

2. Your phone appears to be a carrier branded Samsung Galaxy S5, G900V, for the U.S. CDMA network for Verizon and it would seem to have been adapted with a custom ROM for the International model, G900F, and with United Arab Emirates firmware installed. If you are attempting to use the Verizon messaging service try installing, say, Android Messages, free, from the Play Store and see if that solves your problem.

See, also, #1.6 of 42 Galaxy S5 models - Dummies Guide

You may also find, (if it is indeed a G900V model), that it does not function on the U.K. EE network on 4G/LTE. See... https://willmyphonework.net/