You want to give a client a discount on faulty goods, late delivery or simply a discounted credit
You have three options...
> Create the Credit Note
> Input the correct quantities
> Amend the line value per each product to 30%
> The total on the credit note will be correct
> Use the comments field for additional notes
> Create the Credit Note
> Input the correct quantities
> Set the discount to 70%
> The total on the credit note will be the correct 30% you want
> Use the comments field for additional notes
To do it directly on invoice you have the option to set a discount by value, and not by percentage, by switching on the dropdown field on the discount line.
Calculate what the discount should be and add it as value.
> Use the comments field for additional notes