@ksa1
Is this a brand new SIM and connection, or is it a replacement SIM for an existing line?
For brand new SIM & line, you'd need to pop the SIM card into a device and also make a first phone call while in the UK to activate the SIM card. It's not possible to activate it any other way.
If it's simply a replacement SIM card for an existing number you can activate your new SIM online at Activate Your SIM page. You'll need to have the previous old SIM card active and working to complete this.
Ali
