sms signature, never put any can't remove

[mebenn]

umm...
I have an xperia z1 and I've look thru a loads of forum to remove the sms signature, but never found how... I never put any signature on this phone but, my last phone was an xperia arc and before you put some low  upgrade I could have put a sig on my sms but after the upgrade the option disappeared... Don't know why you super developer remove option when they upgrade... Anyway my signature is still on every sms I send even if I change phone even if I change Sim card. So if someone on the Sony forum could help me I'm about to boycott Sony ..

[mebenn]

Very nice that you Sony ppl don't even get me to an answer about my question... Is there any way I can get any kind of help in here...

[Rickard]

The default messaging app in the phone doesn't have any signature so that sounds strange. Are you sure that you're using our app called "Messaging"?
I've also heard that some operators can add a signature to messages. Have you check with your operator so that it's not the network?