How FairMark works

The calculation

FairMark = (taxes and fees the advert left out + one hold bag) ÷ advertised price × 100. “Left out” means charges every family on that deal must pay: tourist taxes, resort fees and entry documents, each from a published source. The hold bag is our standard: one return hold bag per booking, at that airline's price, the same for every seller and every family size, because a holiday with no hold bag at all isn't realistic. If the deal already includes hold bags, nothing is added. Anything the deal includes is never counted.

• FairMark Gold: 5% or less, including adverts that left nothing out.
• Fair Price: more than 5%, up to 10%.
• Higher gap: more than 10%, up to 20%.
• High gap: more than 20%.

Extras your family adds (your own number of bags, seats together, getting to the airport) are on every receipt and in your true price, marked “advisory”, but they never change the seller's FairMark. Taking three bags or none, the seller is judged on the same standard of one.

When there is no badge

We show “FairMark unavailable”, and say why, when:

• there's no advertised price to compare with;
• some figures are placeholders rather than real, sourced prices;
• too many fees are rough estimates (confidence under 60%);
• we don't yet have the local tax figures for that destination, so “nothing extra” could just mean “we don't know”.

The sellers' leaderboard

• Built from every deal families X-rayed in the last 30 days, as anonymous totals per seller.
• Every deal is re-priced with today's fees for one standard family (2 adults, children aged 7 and 11), so sellers are compared like for like.
• Ranked by the median gap, so one unusual deal can't make or break a seller. Best and worst deals are shown too.
• A seller needs at least 10 checked deals to appear.
• The ✓ needs 30+ deals in 5+ destinations with a median of 10% or less left out. It is earned, never bought, and lost automatically.
• We rank the company selling the deal, not the brand of holiday inside it.

Challenging a figure

Sellers and families can challenge any figure at corrections@truevsad.co.uk. We reply within 14 days. If a fee is wrong, we correct it for everyone, and every receipt shows where each fee comes from.

Every receipt is stamped with the engine version that priced it. Current engine: 0.6.0.

The law behind it

Since April 2025, UK law has required advertised prices to include every fee a customer must pay, such as mandatory taxes and booking fees. The Competition and Markets Authority enforces this. FairMark measures what an advert still leaves out, such as local taxes paid at the hotel, plus one hold bag, which the law treats as optional but almost every family needs. Other optional extras are shown on your receipt so you see your real total, but they never count against the seller.