Can I add a label to show my tax current tax rate on the invoice like VAT 21% or VAT 0% ?

Applies to Instant Invoice 10 only
You can simply add an expression for this. At the layouts, add a new text object or double click the existing Tax label, delete any existing expression and copy and paste the following :

VAT [DocData.”f_Tax1Rate”]%

[DocData.”f_Tax1Rate”] is the tax rate so if your VAT rate is 21% or 0%, the expression will return :

VAT 21% or VAT 0%

If you need to add a conditional expression like when the VAT is 0, you want to print “Tax Exempt”, you can try :

[IIF(<DocData.”f_Tax1Rate”>=0, ‘Tax Exempt’, ‘VAT ‘ + FloatToStr(<DocData.”f_Tax1Rate”>) + ‘%’ ) ]

So if VAT is 0 it will print : “Tax Exempt”
if VAT is 21%, it will print : VAT 21%