Can a single Avast account be used on multiple devices?

I was wondering if I bought the upgraded version of Avast clean up & the mobile security, would I be able to use them on all of my devices? Or is it only good for 1 device?

Hi,

I take it by “upgraded version” you are referring to a paid subscription. To use an application on multi-devices, you need to purchase a multi-device subscription. Either for a specific application or as a bundle (several applications under one subscription). Please see this guide: https://www.avast.com/en-ww/compare-antivirus