Windows to iOS transfer

Hello Lee, 
Thank you for contacting AVG Community Support.
We understand that you want to use Windows subscription to iOS. We'll certainly check and help you out.
If you have purchased AVG single device subscriptions, it can be used only in the OS mentioned at the time of purchase.
AVG multi device subscriptions can be used in PC and mobile devices.
If you want to change or purchase new multi device subscription, could you please contact our AVG billing & sales team using this link: https://support.avg.com/avg/en/ww/home/current/contact and they will check and help you with best offer.
After clicking the above link, select Account and Billing -> Purchase and Renewal help -> Get Support -> Voice call or Chat.
Thank you and keep us updated.

Can I swap an unused account from windows to iOS

Hello Lee, 
Thank you for contacting AVG Community Support.
We understand that you want to use Windows subscription to iOS. We'll certainly check and help you out.
If you have purchased AVG single device subscriptions, it can be used only in the OS mentioned at the time of purchase.
AVG multi device subscriptions can be used in PC and mobile devices.
If you want to change or purchase new multi device subscription, could you please contact our AVG billing & sales team using this link: https://support.avg.com/avg/en/ww/home/current/contact and they will check and help you with best offer.
After clicking the above link, select Account and Billing -> Purchase and Renewal help -> Get Support -> Voice call or Chat.
Thank you and keep us updated.