From the edit menu select preferences.
Then vat at bottom of left hand menu. Then company preference tab, and top of the window that opens select to track vat then the Vat scheme can be selected and in the drop down box scroll to FRS .
With this selected a extra box will appear where you can set your Vat rate.
Now enter your vat registration data then leave the rest alone and edit the Vat agency to report the periods correctly.