I am VAT registered but the invoices are not showing 20%VAT for customers and I am having to add it on manunally. How do I change this?

Hi tammeravaux-gmai Thanks for reaching out to us here on the Community. The 'Assign default tax code' option within the customers details section isn't an active feature at the present time, it's intended to become an active in the future, therefore you would have to enter any VAT codes manually when creating transactions.