Hi @alid
Providing you’re moving at the start of a new VAT period, you can update the VAT settings on your account by going to Account Settings >> Company Settings >> VAT Settings
You’re not able to switch on QuickFile during a VAT period, but there is a workaround. I’ll try and find the post regarding this and update this post shortly.
[Edit]
Here is the post from @George_H regarding a switch from FRS mid-period: