What VAT is, how it works, when you need to register, and what happens when you do — all in plain English.
VAT (Value Added Tax) is a consumption tax charged on most goods and services sold in the UK. As a business, you act as a collector for HMRC — charging VAT to your customers, reclaiming it on your purchases, and paying the difference over to HMRC.
You're not paying VAT from your own pocket. You're simply the middleman between your customers and HMRC. Understanding this basic mechanic makes everything else about VAT much easier to follow.
The basics of how VAT works in the UK
VAT stands for Value Added Tax. It's a tax on the sale of goods and services, and it's charged at each stage of the supply chain — from manufacturer to wholesaler to retailer to end consumer. The end consumer ultimately bears the cost; businesses simply collect and pass it along.
When you're VAT-registered, you add VAT to your sales invoices (output VAT), and you reclaim the VAT you've been charged on your business purchases (input VAT). At the end of each VAT period, you pay HMRC the difference — or claim a refund if you've paid more than you've collected.
Sells goods for £1,000 + 20% VAT. Charges £1,200 total. Pays £200 VAT to HMRC.
VAT collected: £200Sells for £1,500 + 20% VAT = £1,800. Reclaims £200 input VAT, pays £300 output VAT. Net payment to HMRC: £100.
VAT collected: £300 − £200 = £100 netSells for £2,000 + 20% VAT = £2,400. Reclaims £300 input VAT, pays £400 output VAT. Net: £100.
VAT collected: £400 − £300 = £100 netThe consumer can't reclaim VAT. Total VAT collected by HMRC = £200 + £100 + £100 = £400. Exactly 20% of the final sale price.
Total VAT to HMRC: £400As a VAT-registered business, VAT should be cost-neutral — you charge it out and reclaim it back. It only costs you anything if you sell to non-VAT registered customers (like consumers) who can't reclaim it, making your prices appear higher than non-registered competitors.
Not everything is charged at 20% — here's what to know
There are three main VAT rates in the UK, plus a category for exempt supplies. Getting the right rate on your invoices is important — charging the wrong rate can create problems at VAT inspection.
Zero-rated supplies are still VAT-taxable — just at 0%. You still include them in your VAT return and can still reclaim input VAT on related costs. Exempt supplies are outside the VAT system entirely — you can't reclaim input VAT on costs related to exempt activities.
Some goods and services are exempt from VAT altogether. Common examples include: insurance, finance and banking services, education and training (from certain providers), health services by registered professionals, and most residential property lettings.
If your business only makes exempt supplies, you cannot register for VAT and cannot reclaim any input VAT. If you make a mix of taxable and exempt supplies, you can only partially reclaim input VAT — this is called "partial exemption" and can be complex.
Some transactions are completely outside the VAT system — not taxable, not exempt, just not VAT territory at all. Examples include wages (employer paying employees), dividends, and most grants. These don't appear on your VAT return at all.
The rules around compulsory and voluntary registration
VAT registration is compulsory once your taxable turnover crosses a certain threshold. You can also register voluntarily before reaching it — and there are often good reasons to do so.
You must register for VAT if your taxable turnover in any rolling 12-month period exceeds £90,000. This is not a calendar year — it's any 12-month period ending on the last day of any month. You must register within 30 days of exceeding the threshold.
You must also register if you expect to exceed the threshold in the next 30 days alone (for example, if you've just won a large contract).
Any business can register for VAT voluntarily, even if below the threshold — as long as you're making or intend to make taxable supplies. There are several good reasons to do this early:
Reclaim VAT on purchases: From your registration date, you can reclaim VAT on business costs. You can even reclaim on certain purchases made before registration.
Appear more established: Having a VAT number can signal credibility, especially when selling B2B. Large businesses often prefer to buy from VAT-registered suppliers.
Avoid a sudden cash flow shock: Registering before you hit the threshold gives you time to adjust your pricing and systems gradually rather than all at once.
You can apply to deregister if your taxable turnover drops below the deregistration threshold — currently £88,000. You must deregister if you stop making taxable supplies altogether.
On deregistration, you'll need to account for VAT on any stock and assets you have on which you previously reclaimed input VAT — known as a final VAT return. This can sometimes result in a VAT payment rather than a refund.
Output tax, input tax, and what you actually pay HMRC
Once registered, VAT becomes part of your everyday business. Here's how the core mechanics work in practice.
Output VAT is the VAT you charge on your sales. When you invoice a customer, you add the applicable rate (usually 20%) on top of your net price. The customer pays the VAT to you, and you collect it on behalf of HMRC.
Your sales invoices must include your VAT registration number, the VAT rate applied, the net amount, the VAT amount, and the gross total.
Input VAT is the VAT you've been charged on your business purchases — software subscriptions, equipment, professional fees, materials, and so on. As a VAT-registered business, you reclaim this by deducting it from the output VAT you owe.
To reclaim input VAT, you must hold a valid VAT invoice from the supplier. You cannot reclaim VAT on non-business expenses, client entertainment, or purchases where the supplier isn't VAT-registered.
At the end of each VAT period, you calculate: Output VAT − Input VAT = VAT due (or refund).
If output VAT is higher than input VAT, you pay HMRC the difference. If input VAT is higher (for example, if you've made large purchases or have zero-rated sales), HMRC refunds you the difference.
The VAT you collect sits in your bank account but belongs to HMRC. Many businesses get into trouble by treating it as available cash. A good habit is to move VAT to a separate savings account as you collect it, so it's ready when your return is due.
Simpler alternatives that may suit your business
HMRC offers several alternative VAT accounting schemes designed to simplify administration for smaller businesses. Depending on your turnover and business model, one of these might suit you better than standard VAT accounting.
You account for VAT based on when you actually receive payment — not when you issue an invoice. Similarly, you reclaim input VAT when you pay your suppliers, not when you receive their invoices.
✓ Great for businesses with slow-paying customers — no VAT due on unpaid invoices
✗ Available to businesses with turnover up to £1.35m
You file just one VAT return per year instead of four. You make interim payments throughout the year (monthly or quarterly estimates), then settle the balance with your annual return.
✓ Less admin — one return instead of four
✗ Available to businesses with turnover up to £1.35m. You lose the ability to claim back early VAT refunds.
Instead of calculating exact output and input VAT, you pay a fixed percentage of your gross turnover to HMRC. The rate depends on your industry (e.g. 14.5% for IT consultants, 12% for accountants). You keep any difference between what you charge customers (20%) and the flat rate.
✓ Can be more profitable and much simpler. Less record-keeping.
✗ Available up to £150k turnover. You can't reclaim input VAT (except on certain capital assets over £2,000).
Used mainly for second-hand goods, works of art, and antiques. You only pay VAT on your profit margin rather than the full selling price — useful if you buy goods that already had VAT paid on them when first sold.
✓ Avoids double taxation on used goods
✗ Only applies to specific categories of goods. Cannot show VAT separately on invoices.
The flat rate scheme can be particularly profitable for service businesses with low costs, because you charge 20% VAT to clients but pay a lower flat rate percentage to HMRC. However, if you have significant VAT-reclaimable purchases, standard VAT accounting may be better. Speak to us and we can run the numbers for your specific situation.
What you need to submit and when
Most VAT-registered businesses file a VAT return every quarter. Since April 2022, all VAT-registered businesses must use Making Tax Digital (MTD) compatible software to keep digital VAT records and submit returns directly to HMRC.
MTD requires you to record all VAT transactions digitally using compatible software (Xero, QuickBooks, Sage, etc.). You must record the date, supplier/customer name, net amount, VAT rate, and VAT amount for each transaction.
Total up all output VAT (charged on sales) and input VAT (paid on purchases). The difference is what you owe HMRC (or what HMRC owes you if input exceeds output).
For example, for a quarter ending 31 March, the return is due by 7 May. The return is submitted digitally through your MTD software directly to HMRC.
Payment must reach HMRC by the same date as the return — 1 month and 7 days after your quarter end. Direct debit is the easiest option and gives you an extra 3 days.
HMRC uses a points-based system for late VAT returns. Each late return earns a point. At 4 points (quarterly filers), a £200 penalty is charged, with £200 for every further late return until you reach a zero-point period. Separate late payment penalties also apply on overdue VAT.
HMRC assigns your VAT quarters when you register. Most businesses are on one of three standard stagger periods — quarters ending March/June/September/December, or January/April/July/October, or February/May/August/November. You can request a particular stagger to align with your accounting year-end.
Quick answers to the VAT questions we hear most
Whether you're approaching the threshold, just registered, or want to review your current VAT scheme, we're here to help.