If I have VAT on only part of a bill how do I enter it. It seem to only take 20% or zero of the whole bill
You will need to apply VAT to only a single line of the transaction - so split the transaction between the amount that you do not want VAT to be taken from, and enter that amount in the top line of the transaction with No VAT as the code. Then enter a second line with the amount you need VAT to be taken from, with 20% as the code. This will then only work out 20% of the amount entered in the second line.