Friends number changed to unknown

[Anonymous]

Hiya, I was texting a friend and yet to add her their number to my phone, the phone number was displaying fine up until this morning when it changed to "unknown" both in whatsapp and in my text message inbox. does this mean the number has been cut off? never experienced this before

[jonsie]

Maybe the friend has changed number? Try dialling the number to see if you get a ringtone.

[Anonymous]

Have you rebooted the iPhone?

[Anonymous]

Maybe they changed their settings

[MI5]

Have you removed their contact from your phone by mistake?

[Anonymous]

My mother does it all the time by accident and blocks her number from being sent. It then comes up as unknown on my phone even though the number is correct.