It depends if your tariff changes immediately or at next billing date.
You can check in your MyO2 if the tariff has changed over or not
http://www.o2.co.uk/myo2
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)