They will be on a cloud service, such as Dropbox, Picassa etc so don't take up any space on your phone. You need to go into account settings and turn off the sync for whichever cloud based service you are using if you don't want them to back up anymore, but if your phone crashes you will lose any further photos unless you back up manually.
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)