You've found a house, agreed a figure with the estate agent, and worked out roughly what your deposit and mortgage cover. Then someone mentions Stamp Duty, and you realise you've no idea whether that's a few hundred pounds or a few thousand, or whether you even have to pay it at all as a first-time buyer. That gap between "roughly what I think I owe" and "what HMRC actually wants on completion day" is where plenty of first-time buyers get caught out, sometimes for thousands of pounds more than they expected.

Here's the number that catches people out hardest: a first-time buyer purchasing at exactly £500,000 pays £10,000 in Stamp Duty. A first-time buyer purchasing at £500,001, one pound more, pays roughly £15,000. That's not a typo. Relief doesn't taper off above £500,000, it disappears completely, and you fall onto standard rates for the entire price (HMRC Stamp Duty Land Tax rates, checked September 2026). This article works through exactly how the bands apply at every price point, so you know your real number before you make an offer, not after you've exchanged.

How Stamp Duty actually works: bands, not a flat rate

Stamp Duty Land Tax (SDLT) applies in England and Northern Ireland only, and it's charged in slices, the same way income tax is, not as one flat percentage of the whole price. For a first-time buyer, the current bands are: 0% on the first £300,000, then 5% on the portion between £300,000 and £500,000 (HMRC SDLT rates, checked September 2026). Above £500,000, first-time buyer relief stops applying altogether and you move onto the standard rates below.

Worked example: a first-time buyer paying £350,000 owes nothing on the first £300,000, then 5% on the remaining £50,000, which is £2,500 in total. A first-time buyer paying £450,000 owes 5% on £150,000, which is £7,500. Neither of those numbers is obvious if you assume Stamp Duty is either "zero for first-time buyers" or "a flat percentage of the price", and both assumptions are wrong.

So if you're budgeting for a first home anywhere above £300,000, build the actual band calculation into your completion-day costs now, because the further above £300,000 you go, the faster that bill grows.

The £500,000 cliff-edge, and why it exists

The rule most first-time buyers don't know is that the relief is an all-or-nothing threshold, not a fading benefit. HMRC's guidance is explicit: above £500,000, no first-time buyer relief applies at all, and the purchase is taxed under the standard residential bands instead, which start from 0% up to £125,000, 2% up to £250,000, and 5% up to £925,000 (GOV.UK SDLT guidance, checked September 2026).

Run the numbers either side of the line and the gap is stark. At £500,000, a first-time buyer pays £10,000 (0% on £300,000 plus 5% on £200,000). At £500,001, that same buyer loses the relief entirely and is taxed on the whole amount under standard rates: 0% on the first £125,000, 2% on the next £125,000 (£2,500), and 5% on the remaining £250,001 (roughly £12,500). That comes to about £15,000, roughly £5,000 more than at £500,000, for a single extra pound on the purchase price.

A £1 increase in purchase price can add roughly £5,000 to a first-time buyer's Stamp Duty bill, purely because it crosses the £500,000 relief threshold.

So if your offer or a counter-offer is hovering anywhere near £500,000, that cliff-edge is worth negotiating over harder than almost any other line item in the deal, because £1 in the wrong direction is a five-figure mistake.

What if you're not a first-time buyer, or you're buying outside England?

Standard residential rates apply if you've owned property before, or if any other buyer named on the purchase has, even if you personally haven't (GOV.UK SDLT guidance, checked September 2026). HMRC's first-time buyer test looks at every buyer on the title, not just one of you, which is a common trap for couples where only one partner is buying their first home. On a £350,000 purchase, a standard buyer pays £7,500 against a genuine first-time buyer's £2,500, a £5,000 difference for the identical property.

Buying a second home or a buy-to-let adds a further 5% surcharge on top of the standard bands, on any additional residential property costing £40,000 or more, so the same £350,000 purchase would cost a landlord roughly £25,000 in total once the surcharge is added. That's a central reason many landlords now run the numbers on buy-to-let cash flow after Section 24 before committing to a purchase, since the up-front tax bill compounds an already tighter margin.

None of this applies if you're buying in Scotland or Wales. Scotland charges Land and Buildings Transaction Tax with its own bands and its own first-time buyer relief up to £175,000, and Wales charges Land Transaction Tax, also with separate thresholds. If you use an SDLT calculator for a Scottish or Welsh purchase, the number it gives you will simply be wrong.

So if you're buying with a partner, check both of your ownership histories before you assume first-time buyer relief applies, and if you're buying north or west of the English border, use the correct nation's calculator, not this one.

The maths, in one place:

First-time buyer, £350,000: £2,500 Stamp Duty (0% to £300k, 5% on the remaining £50k).
First-time buyer, £500,000: £10,000 (0% to £300k, 5% on the remaining £200k); the maximum relief still applies here.
First-time buyer, £500,001: roughly £15,000 (relief withdrawn entirely, standard bands apply to the full price).
Standard (non-first-time) buyer, £350,000: £7,500 (0% to £125k, 2% to £250k, 5% on the remainder).
Second home or buy-to-let, £350,000: roughly £25,000 (standard rate plus the 5% additional-property surcharge).
All figures based on HMRC SDLT rates for England and Northern Ireland, checked September 2026. If you're a first-time buyer and unsure whether you qualify, check the Stamp Duty calculator before you offer, using the exact price you intend to bid.

One more trap worth knowing before you get this far: some first-time buyers assume their deposit size or their credit score is what determines their Stamp Duty rate. It isn't. Stamp Duty depends entirely on the purchase price and whether every buyer genuinely qualifies as a first-time buyer, not on how you're financing the purchase or how strong your credit file is. Leasehold flats and houses are taxed identically to freehold ones for SDLT purposes too, though our leasehold versus freehold guide covers the separate costs that catch leasehold buyers out later, such as ground rent and service charges.

What this means for you

If your purchase price sits comfortably under £300,000 as a genuine first-time buyer, your Stamp Duty bill is zero and you can stop worrying about this particular cost. If you're anywhere between £300,000 and £500,000, budget the 5% marginal rate on the amount above £300,000 into your completion-day cash, not your mortgage, because SDLT is due within 14 days of completion and lenders don't fund it. And if you're negotiating a purchase price that sits close to £500,000, the maths points toward treating that threshold as a hard ceiling worth defending in negotiation: agreeing £499,950 instead of £500,500 isn't a rounding difference, it's roughly £5,000 in your pocket. Most people who run these numbers properly end up structuring their offer around the band, not the asking price, and once you've moved in, our new homeowner checklist covers the costs that follow completion day.