If your tariff has changed already you can start using your new allowances... Check in your My O2 for how many calls, texts and data you have, but you may not get the full package until the 1st.
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)