Actually, it's probably Family Plan you would be eligible for
https://www.o2.co.uk/family-plan but again, you must apply within 30 days.
If you are on refresh just buy your phones (no discount on them anyway) a you can cancel the airtime for free.
Get your phones unlocked first though so you can use them on another network on a sim only tariff.
https://community.o2.co.uk/t5/Other-Products-and-Services/Unlocking-an-O2-phone-to-use-a-different-S...
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion.
This is not Customer Service so we are unable to help with account specific issues.Currently using:
Pixel 7a (O2 & Lyca), One Plus 6 (Sfr), iPhone 12 Pro Max (Vodafone)