What a UK buyer is actually charged on Gumroad — 28 of 32 stores measured

Every product page below was loaded logged out from London, then its own “I want this” control was followed to Gumroad’s checkout and the checkout was read. 28 of the 32 stores we could read charged more at the pay step than the page advertised, a median of 21.2% more (range 16.6%–27.9%). The extra is VAT, added on top.

What each store advertised, and what the pay step totalled

The ones we could not read — 1 of 33

Listed rather than dropped. A percentage whose denominator quietly excludes the awkward cases is not a measurement.

Where the difference comes from, and it is not one thing

The headline figure looks like a tax rate and is not one. The pay step itemises a subtotal as well as a tax, and the subtotal is not the price the page advertised. Two effects stack:

• Tax on the subtotal: median 20.0%, range 18.7%–20.9% across 28 readings. Tight enough to read as a single statutory rate.
• A drift between the advertised price and the amount actually taxed: median 0.9%, range -3.6%–7.7% across 29 readings. The displayed price is converted for the visitor and the charged one is rounded separately, so the number being taxed is not the number that was quoted.

Both figures use only readings where the page and the pay step quoted the same currency — across a currency change the difference is an exchange rate, not a drift. Excluded from both: the one store published as our own misread — its page price was read wrong here, so its page-to-subtotal difference is our error and not a drift. Neither component is hidden and neither is large alone; the compounded number is the one a buyer meets.

Method, in full

• 33 stores walked, 32 read, 1 not read. 28 charged more at the pay step, 1 matched the page, 1 came out lower — that last group is almost certainly us misreading the page price (a pay-what-you-want minimum or a struck-through price), not a discount, and it is counted in the denominator rather than thrown away. 2 switched currency between page and checkout.
• 32 of the stores were drawn from 4,255 sellers with a fixed seed (20260809), eight from each of four price bands, before anything was walked. The draw is reproducible from the same CSV, so nobody — including us — can re-roll it until the result looks better. The remaining 1 is our own product, added on purpose: a page that reports a platform's behaviour and exempts its own author from it is worth less than nothing.
• Two page loads per store and nothing else. The product page, then the gumroad.com/checkout URL the page’s own buy control carries. No order was completed, no form was submitted, no email or card was typed into anybody’s checkout, and no account was touched. It is what a buyer who thinks twice and leaves does.
• From London, GB. A buyer somewhere without VAT sees a different number, and that is the point — the difference is a function of where the buyer is, which is precisely the thing the seller cannot vary from inside their own account.
• Read on 2026-08-09. Prices move; re-run it yourself. The reader is open source and the raw records for this page are in data/checkout-audit.json.

What a seller can actually do

Not much, and it is better to say so than to invent a fix. You cannot turn it off; you are not supposed to. What you can do is stop being surprised by it:

• Know your own number. Open your product page in a private window from a VAT country and follow your own buy button. It takes a minute and it is the only way to see what your buyer sees.
• Say it on the page. A line saying tax is added at checkout for EU/UK buyers costs nothing and removes the surprise at the exact step where surprise loses the sale.
• Compare like with like. When you benchmark your price against a competitor, you are reading their pre-tax number and your buyer is paying a post-tax one.