Work
Invoice Total Calculator
Enter a subtotal, apply a discount and choose a VAT rate — get your final invoice total.
How it works
Total = (Subtotal − Discount) × (1 + VAT rate). The discount is applied to the subtotal first to get the net amount, then VAT is calculated on the net. This matches standard UK invoicing practice.
Frequently asked questions
When must I charge VAT?
Once your taxable turnover exceeds £90,000 in any rolling 12-month period, VAT registration becomes mandatory.
Should discount be applied before or after VAT?
In the UK, discounts are applied to the net (pre-VAT) amount. VAT is then calculated on the discounted net. Our calculator follows this convention.