Hey!

My dad has a Nokia Lumia 800 on O2 and this morning the SIM card just stopped working, it's saying NO SIM, we thought it was the phone but upon trying my mates O2 SIM in the phone it works fine, we thentried my dads O2 SIM in my mates iPhone and it said NO SIM on there too... Does anyone have any ideas why this has happened or what exactly the cause may be?

Will be calling O2 tomorrow morning.

Cheers

Sounds like his sim has been cancelled?

He had the phone replaced yesterday because it developed a fault, they gave him a new Lumia 800 but kept the SIM, do you think the SIM may have been deactivated in that process for some strange reason?

If the error is "No Sim" and only happens with his sim that means his sim card is faulty and will need to be replaced. He should be able to get one from an O2 shop, but may be worth ringing them first

Cheers yeah i'll ring up tomorrow