VAT Exempt transactions

I have two tax codes set up as VAT exempt. One is meant to be zero rated and therefore net sales/ purchases show on VAT return but no VAT is applied and one is meant to be VAT exempt which is meant to be excluded in its entirety from the VAT return.

Currently both net values get pulled through on to the VAT return and there we have to manually adjust it before submitting. Does anyone know how I ensure the exempt one does not get caught up in the VAT return?

For latter part, use exempt field (available in Invoice->line). There you can type YES and that line will be exempted from VAT (even if it has VAT attached to it)