Unable to call one number
Hi @Saintsman
Are you sure the contact is actually receiving your texts? If you are getting an invalid number message it sounds as if the phone may have been disconnected....or blocked you as a sender
You could try deleting the number and then re-adding it...Reboot your phone
Best of luck and welcome to the forum 
Well I'm stumped. Unless you need a new sim?
.
Rather similar to my experience at the weekend. Though it was texts from my husband I couldn't receive.
He could call me but texts weren't getting through, even when he sat next to me.
However an hour later they all came through in a mad rush....9 of them so I put it down to network congestion.
I did think she may have inadvertently blocked your number.....you could look at that...though you are still are able to text her. Worth a look though?
Are you calling her from your contacts or just dialling the number from your keypad?. Try adding +44 before her number in contacts is the only other thing I can suggest...
Definitely be looking at her phone. Go int call settings. then message setting to check which numbers she has blocked or set to auto reject or other wording
Welcome to the forum, @Saintsman 
Any luck with the latest suggestions our members have shared above? Please do let us know how you get on with this!
→ Access for You: Registration - Find out how to register for our Access for You service.
→ Want to chat with other fellow-minded members? Head to our Off-topic section for some interesting chit-chat.
→ Check out our Priority board for tickets & offers updates, and to discuss all things Priority-related!
→ Welcome to O2! - New to O2? Find out all you need to know to get started!
If you'd like to take part, why not register? 
