o2 Referral for a friend

Hello,

I am trying to understand the terms and conditions of referral program.
I wanted to refer my friend with a just mobile phone contract. I mean just the phone no need of sim. Because she already has an o2 sim. Would I get the referral amount for this case. Also does these referral program work only with selected phones and traiffs. Another question is since she is also a student can't i get additional 5EUR discount with the existing referral program. I am planning to buy Samsung S9, just the phone contract.

Regards,
Kiran