"Welcome bonus: get 150% up to £150 on your first deposit". It's the kind of offer that greets anyone who visits a British online betting site. What it doesn't say is that if you decide to spend £50 on this offer, you'd need to stake an additional £750 of your own money before any winnings could be withdrawn.
Recent research by colleagues and I asked nearly 600 UK bettors to work out the true cost of exactly that kind of offer. Nearly everyone got it wrong, underestimating the real amount often by hundreds of pounds.
Financial inducements , "free" bets, deposit matches and welcome bonuses are a standard part of signing up with almost any UK operator. Their behavioural harms are well established. They encourage people to gamble more often, push bettors towards riskier wagers and are linked to chasing losses. The heaviest effects tend to fall on those already experiencing gambling harm.
But behaviour is only half the story. Harm can also stem from something more basic: not understanding what an offer actually requires of you in the first place. That's where wagering requirements come in - the rules saying you have to bet the bonus amount a certain number of times over before any winnings attached to it can be withdrawn.
Until recently, these multipliers could be as high as 50 times the bonus. Since January 2026, the UK Gambling Commission has capped them at ten times and required operators to make their terms clearer. It's a meaningful step. But it stops short of requiring operators to show consumers what that ten times multiplier actually means in pounds and pence, and that omission turns out to matter.
Our research
We ran an online experiment with 585 adults who had gambled in the past year. Each participant saw a realistic welcome bonus modelled on a real 2025 promotion, fully compliant with the 2026 rules. Half saw it in the standard industry format. The other half saw the same offer with one addition: a three-sentence example spelling out what the 10 times wagering requirement actually meant for a £50 deposit.
The correct answer was £750. The median estimate was £500. More than 90% of participants underestimated the true cost. Only around 5% got it right.
The £500 figure is telling. It is exactly what you would get if you applied the 10-times multiplier to the £50 deposit but ignored the 150% bonus on top. Most people understood part of the calculation but missed the compounding effect.
Matched bonuses combined with wagering multipliers are among the most common inducements in the UK. Together, they appear to obscure the true cost in a systematic way.
Crucially, this misunderstanding was not confined to any one group. People at low risk of gambling harm miscalculated at almost the same rate as those at high risk. The issue is not that some bettors are bad at maths. It is that the offer itself is structured to make the true cost hard to calculate.
When we added the worked example, attractiveness ratings dropped significantly. Once people could see what the offer required, they found it far less appealing.
What bettors told us
Participants' responses revealed three consistent themes. Many described the offers as manipulative, using words such as "predatory" and "deceptive". Others argued they were economically worthless, with one participant saying "99% of people will fail to benefit". Many also called for stronger regulation.
Several made a comparison worth taking seriously: gambling inducements, they argued, should follow the same upfront disclosure rules as credit products. One 23-year-old said wagering requirements should be shown on the advert itself, "similar to how interest rates need to be shown clearly on sites offering loans".
They may have a point. The Annual Percentage Rate was introduced in UK consumer credit precisely because people couldn't compare loan products when costs were hidden behind different headline formats. Gambling inducements present an almost identical problem.
Capping wagering requirements at ten times is welcome. But it's not the same as making costs visible. Even a reduced multiplier still requires a multi-step calculation, and an understanding of compounding that many people do not have.
A worked example, shown in the same print size as the headline offer, would take only a few lines. It would not ban anything or restrict choice. But our study suggests it would change how people evaluate these offers. Denmark already requires something similar. Australia , Spain, Belgium and Italy have gone further, banning inducements to new customers altogether.
Worked examples are not a complete solution. But as a low-cost addition to existing Gambling Commission rules, they could help consumers see these offers for what they are before deciding whether to take them up.
Jamie Torrance has received, in the last three years: (1) Open access publication funding from Gambling Research Exchange Ontario (GREO), (2) Conference travel and accommodation funding from the Academic Forum for the Study of Gambling (AFSG), (3) A minor exploratory research grant from the ASFG and GREO, (4) Seed Grant funding from the International Centre for Responsible Gambling (ICRG), (5) Studentship funding from the Economic and Social Research Council (ESRC), (6) Rapid evidence review (RER) funding from UK Research and Innovation (UKRI), (7) Policy Fellowship funding from UKRI, and (8) A Gambling Harms Research and Innovation Partnership (GHRIP) award from UKRI.
