insert valid sim card

[Anonymous]

Hi from last few days I automatically get a note on my phone screen ''Network unavailable restart your phone with valid sim card''. I have to tap restart option and the phone starts working okay. I am on monthly contract and have Note 4. Any advise please.thank you. Kash

[MI5]

First thing to try would be a new sim card.
Contact CS or call into any O2 shop and they will sort you out.
http://www.o2.co.uk/contactus

[Anonymous · Accepted solution]

Hi

Try the SIM card in another phone as a process of elimination.

If It continues look at http://status.o2.co.uk

And an O2 shop can swap your sim over in store too.

[jonsie]

Try removing and cleaning the sim card first. .....