When you sell something as a VAT-registered business, the tax you add to the price is output VAT — money you collect for HMRC, not income you keep.
One of the first things that changes when a business crosses the VAT threshold is that part of every invoice stops being yours. The 20% you add to a £100 sale is not extra profit; it is tax you are collecting for the government. That collected amount is your output VAT.
When you make a taxable sale, you add VAT at the appropriate rate on top of your price. The customer pays the full VAT-inclusive amount; you keep your net price and set the VAT portion aside. At the end of each VAT period (usually a calendar quarter), you total all the output VAT you charged and report it in Box 1 of your VAT return. The figure you actually pay HMRC is that total minus the VAT you paid on your own purchases, so output VAT is only half of the calculation, but it is the half that customers fund.
The rate of output VAT you charge depends entirely on what you are selling, not on who you are. There are three main UK VAT rates for 2025/26:
A fourth category, exempt supplies (such as insurance, postage stamps and certain financial and education services), sits outside the VAT system entirely. Exempt sales carry no output VAT and, unlike zero-rated sales, can restrict how much input VAT you are allowed to reclaim. Getting the classification right matters, because charging the wrong rate of output VAT means either short-changing HMRC or overcharging your customers.
Imagine Priya runs a VAT-registered design studio. In one quarter she invoices clients £40,000 plus VAT.
In the same quarter she buys software, equipment and subcontractor services costing £10,000 plus £2,000 of input VAT.
Her VAT return nets the two figures:
| Item | Amount |
|---|---|
| Output VAT (on sales) | £8,000 |
| Input VAT (on purchases) | £2,000 |
| VAT payable to HMRC | £6,000 |
Priya pays HMRC £6,000. The full £8,000 of output VAT was collected from clients, so the only money leaving her own pocket is the tax on the value she added — the £30,000 difference between her sales and her purchases, at 20%. This is exactly why VAT is described as a tax on value added rather than a tax on the business itself. You can model this for your own turnover with the VAT calculator.
The mechanics also explain why the rate at which you charge output VAT is fixed by the product, not by your costs. If Priya raised her prices, her output VAT would rise in proportion, but so would the amount her clients reclaim if they are VAT-registered themselves. For business-to-business sales, output VAT is largely invisible because the buyer reclaims it; for sales to consumers and to non-registered businesses, the VAT is a real cost they cannot recover, which is why it ultimately rests with the end consumer.
Because output VAT is collected long before it is paid to HMRC, it can quietly inflate a bank balance and tempt a business into spending money that is not really theirs. A sole trader who treats a VAT-inclusive turnover as profit will find the quarterly return a painful surprise. Disciplined businesses ring-fence the VAT element of each sale, often by moving it into a separate account the moment a customer pays, so the bill is fully funded when it falls due.
Under Making Tax Digital for VAT, all VAT-registered businesses must keep digital records and submit returns through compatible software, which makes tracking output VAT accurately more important than ever. The cash accounting and flat rate schemes can change exactly when and how much output VAT you account for, but the underlying principle does not move: the VAT you add to a sale is owed to HMRC, not earned by you.
Output VAT feels like income on the day a customer pays, but it is a debt to HMRC from the moment you charge it.
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