If you're invoicing a client for £100 — perhaps for a single task, a fixed-fee service, or a line item on a larger invoice — here's exactly how VAT works.
Create VAT Invoice for £120 →
HMRC-compliant · pre-filled · free · no signupHere are practical examples of how £100 plus 20% VAT applies to common UK business situations.
UK Business Example
Invoice line item or small service fee
Net: £100 + VAT: £20 = £120
On Your Invoice
Show £100 as the net amount, £20 as VAT (20%), and £120 as the total amount due.
Reduced Rate (5%)
If 5% VAT applies: £100 + £5.00 VAT = £105.00 total
The UK standard VAT rate is 20%, set by HMRC. To add 20% VAT to any net amount, multiply by 1.20. This is the official HMRC formula used by all UK VAT-registered businesses.
HMRC Formula — Add VAT
£100 × 1.20 = £120
Net × (1 + VAT rate) = Gross
VAT amount only
£100 × 0.20 = £20
Net × VAT rate = VAT amount
If £100 is the gross (VAT-inclusive) price, you need to divide by 1.20 to find the net amount. This is called reverse VAT or removing VAT.
£100 ÷ 1.20 =
£83.33 net
VAT element: £16.67
HMRC source: The UK standard VAT rate of 20% is set by HM Revenue & Customs. All VAT-registered UK businesses must charge VAT at this rate on standard-rated supplies. Verify at HMRC GOV.UK →
Need to calculate VAT on a different amount? Use our free UK VAT calculator.
Calculate VAT Now →Other common UK VAT amounts — click any to see the full breakdown.