What Is VAT? The Chain, the Reclaim and the Threshold

VAT is charged at every stage of production, collected by every business in the chain, and paid in full by exactly one person: the final consumer. Everyone in between hands over the tax they charged and takes back the tax they were charged, so the amount they part with is the tax on the value they added — which is where the name comes from.

That mechanism explains almost everything else about VAT: why businesses can reclaim it, why registration thresholds exist, why a zero-rated business would voluntarily register, and why VAT and sales tax behave differently despite looking identical on a receipt. This page is about the mechanism. If you want the arithmetic — adding VAT, stripping it out, working backwards from a gross figure — the VAT calculator covers it in detail.

Only the Last Person in the Chain Actually Pays It

Follow a table from forest to living room, at a 20% rate. Each business charges VAT on what it sells and reclaims the VAT on what it bought.

The government collects £20 + £40 + £80 + £60 = £200, which is exactly the VAT the consumer paid at the till. Nothing was taxed twice, and no business is out of pocket. Each one remitted 20% of the value it added: £100, £200, £400 and £300 of added value, taxed at £20, £40, £80 and £60.

This is the property that makes VAT collectable at scale. The tax arrives in instalments from every business in the chain rather than depending entirely on the last shop getting it right, and each business has a documentary reason to want a proper invoice from its supplier.

Input VAT, Output VAT, and What You Reclaim

Two terms cover the whole of a VAT return, and mixing them up is the most common bookkeeping error a newly registered business makes.

• Output VAT is the VAT you charged your customers. It was never your money.
• Input VAT is the VAT your suppliers charged you. You get it back.

Your return is the difference. Charge £9,000 of output VAT in a quarter and incur £3,500 of input VAT, and you pay £5,500. If the figures run the other way — a quarter of heavy equipment purchases against modest sales — the balance is a refund rather than a bill. That is what people mean by reclaiming VAT: it is not a rebate scheme, just the ordinary result of the subtraction coming out negative.

The practical consequence is that output VAT sitting in your bank account is not revenue. Businesses that spend it and then meet a quarterly bill they had not budgeted for are the single most common VAT casualty. Moving the VAT element into a separate account as it comes in removes the problem entirely.

What You Cannot Reclaim

The right to reclaim input VAT is narrower than it first appears, and the exclusions are where honest mistakes happen.

• Anything without a valid VAT invoice. A card receipt is not enough. The invoice needs the supplier's VAT number and the VAT shown separately, and without it the claim fails no matter how genuine the expense.
• Business entertainment. Entertaining clients is generally blocked, while ordinary staff subsistence is generally not — a distinction that catches people out constantly.
• Cars. VAT on a car is usually irrecoverable unless it is used exclusively for business, which in practice means no private use at all. Vans and commercial vehicles are treated differently.
• The private portion of anything. A phone used 70% for work supports a claim on 70% of the VAT, not all of it, and the apportionment needs to be defensible.
• Goods bought under a margin scheme. Second-hand items sold under those rules carry no reclaimable VAT, because the seller only accounted for VAT on their margin.

Registration, and Why Some Businesses Volunteer

Registration is compulsory above a turnover threshold — currently £90,000 in the UK, measured on a rolling twelve months rather than a tax year, which is the part people miss. It is not a calendar-year test, so a strong autumn can trigger registration in the middle of a quiet year.

Below the threshold, registration is optional, and whether it helps depends entirely on who your customers are. If you sell to VAT registered businesses, they reclaim whatever you charge, so your prices are effectively unchanged to them while you gain the ability to reclaim your own input VAT. If you sell to consumers, registering makes you 20% more expensive or 20% less profitable, and there is no third option.

The clearest case for volunteering is a business making zero-rated supplies — most food, children's clothing, books, some exports. Zero-rated is not the same as exempt: a zero-rated business charges VAT at 0% but is still making taxable supplies, so it can reclaim input VAT in full and will be in a permanent refund position. An exempt business charges no VAT and cannot reclaim anything, which is a considerably worse place to be.

VAT and Sales Tax Are Not the Same Mechanism

Both add a percentage at the point of purchase, and there the similarity ends.

The last row is why more than 170 countries use VAT. A single-point tax collects nothing when the final sale escapes it; a staged tax has already banked most of the money by then.

The shelf-price row is the one that surprises visitors in both directions. A price marked £12 in a British shop is £12 at the till. A price marked $12 in most of the United States is not.

Rates Vary More Than People Expect

There is no international standard rate, and the spread is wide. These are standard rates, and most countries also run reduced rates for particular categories.

Rates move, and a table on any website ages. Treat these as an indication of the spread rather than a source to file a return against, and confirm the current figure with the relevant tax authority before it matters. Some systems do not have a single standard rate at all: India's GST runs several slabs, and Canada layers a federal tax with provincial ones.

Where VAT Goes Wrong for Small Businesses

• Treating a gross figure as net. Applying 20% to a price that already includes VAT overstates the tax. Extracting VAT from a gross amount means dividing by 1.2, or multiplying by 1/6, not subtracting 20%.
• Missing the rolling threshold. Turnover is tested over any twelve months, not a tax year, and the obligation starts from the point it is crossed.
• Confusing zero-rated with exempt. Both show no VAT on the invoice and they have opposite consequences for what you can reclaim.
• Assuming a flat-rate scheme is simpler and cheaper. It is simpler. Whether it is cheaper depends on how much input VAT you would otherwise reclaim, and a business with significant purchases usually loses on it.
• Ignoring where the customer is. Cross-border digital sales are generally taxed where the customer belongs, not where you are, which can mean accounting for several countries' VAT from a single laptop.

None of these are arithmetic failures, which is the pattern worth noticing. The sums are the easy part; the definitions are where the money is lost.