How do i add vat to my invoices

Hello Bsaturfandag-gma, 

Welcome to the Community page, 

You might need to turn on tax first on the taxes tab if you have not already done so, if you have then when you go to +new> invoice> on the right hand side it will say amounts are in the box if it is set at no vat it will not show the vat box for you. If you change it to inclusive of tax or exclusive of tax, the VAT box will then appear for you to select the correct vat code for that line.