You can just swap the phone sim over no problem but the other sim won’t be any good as it’s blank so you will need a data sim for the iPad.
You can have either a contract one or PAYG.
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)