on 09-02-2019 16:36
This isn't customer service so you need to call them on 202 and give 30 days notice.
Help here @::
on 09-02-2019 20:07
Are you PAYG or contract? (Your post states PAYG)
If so, no need to do anything.
The payg accounts will deactivate after around 6 months of non use or top up.
The SIM cards will then be defunct.
on 09-02-2019 20:32
Don't forget to cancel your auto top up https://autotopup.o2.co.uk/o2uk/FAQ.aspx
OnePlus 6 (O2 & Sfr), Z3 Tablet (Three UK), iPhone7 (EE)