What counts as suspicious betting
A single large bet is not suspicious on its own. Bookmakers take big stakes every Saturday. What draws attention is a bet that does not fit: an account that only ever bets small amounts suddenly placing a heavy stake on a booking market, or several unrelated customers backing the same unlikely outcome within minutes of each other.
The concern is always one of two things. Either someone knows something the public does not, such as a team selection, an injury or a planned booking, or someone has arranged for the event to go a particular way. Suspicious betting is the trail those two situations leave behind, and it is often the first visible sign of either.
Integrity in this sense means the event is genuine and the market is fair. A booking, a missed penalty or a lost frame is only worth betting on if nobody involved has decided it in advance. When that trust breaks, honest customers lose money on prices that were wrong, and the sport loses the reason anyone watches it.
Football and tennis dominate every set of figures on this page. Both offer a vast number of matches and markets, from top divisions down to small tournaments, so they give the monitors the most to watch. Table tennis and esports also rank high in the alert counts, with 34 IBIA alerts each in 2025.
How bookmakers monitor accounts and stake patterns
Bookmakers start from the account. Every licensed online operator must verify a customer’s age before they can deposit and their identity before they can bet, a rule in force since May 2019. That gives traders and risk teams a known person behind each stake, with a betting history they can compare against any new bet that looks out of character.
Stake patterns are the next layer. Risk teams look at the size of a bet against the customer’s usual range, the market chosen, the timing in relation to team news, and whether linked accounts are betting the same way. Niche markets with low liquidity, such as cards or individual player events, attract closer attention than the match result.
Linked accounts matter because insiders rarely bet in their own name. Martin Sherif, the Everton forward fined £5,000 in October 2026, had opened and funded accounts that other people used to place 61 bets on football. Shared payment details, devices or addresses are the kind of connection a bookmaker can spot internally that no outsider would ever see.
Timing completes the picture. A run of stakes on one outcome just before team news is published, or just before a market is suspended, tells a trader more than any single bet. You can see why lower-league and niche events worry bookmakers most: thinner markets move further on a small amount of money, so unusual activity stands out faster.
Market alerts and the international integrity monitors
Beyond their own books, most large operators feed data into shared monitoring systems. The best known is run by the International Betting Integrity Association, an operator-run body. Its members report unusual activity to the association, which records the concern as an alert and can pass it on to the sport concerned.
IBIA’s figures for 2025, reported in early February 2026, showed 300 alerts, up 29% from 232 in 2024 and the highest in the five years the report covers. Football produced 110 of them, or 37%, and tennis 74, or 25%. Table tennis and esports each accounted for 34 alerts, basketball 27, across 16 sports in total.
The association said its data contributed to 54 matches being proven corrupted in 2025 and to sanctions on 24 players, teams and officials in five sports. Its platform watches over 1.5 million matches a year in more than 80 sports, and covers more than US$300bn in annual betting turnover. Those numbers come from trade press reports of its release.
Sportradar runs the other widely quoted system, the Universal Fraud Detection System. Its 2025 report, published on 10 February 2026, said it monitored over a million events across 70 sports and found 1,116 suspicious matches, about 1% fewer than in 2024. Football accounted for 618, basketball 233, tennis 78, table tennis 65 and cricket 59.
The same report said 682 suspicious matches had been flagged by its automated detection models, up 56% from 436 a year earlier, and that its work supported 125 sanctions across seven sports. Football’s total fell from 730 to 618. Those are counts of matches flagged, which is a different measure from matches proven corrupt.
Sharing information with the SBIU and sports bodies
In Great Britain the formal destination for concerns is the Sports Betting Intelligence Unit, part of the Gambling Commission. It takes reports of suspicious betting, misuse of inside information, breaches of sports rules and Gambling Act offences from bookmakers, governing bodies, law enforcement and the public. Football and tennis produce the largest share.
The Gambling Commission’s impact metric tracks the volume quarter by quarter. It recorded 135 unusual or suspicious betting reports from July to September 2025, 152 from October to December, 140 from January to March 2026 and 132 from April to June 2026. Across 2025-26 the total reached 587, up from 501.
Sports bodies are the other half of the exchange. The FA, the Darts Regulation Authority and the snooker authorities each investigate under their own rules, and the intelligence unit passes information to them. In the Kyle McKinstry darts case, which ended in an eight-year ban in 2020, the unit was among the bodies that assisted the investigation.
The unit’s engagement figures show how much of this is relationship work. It engaged with 369 stakeholders in 2025-26, up from 327 the year before. A report from a bookmaker is far more useful when the sport can match it against its own information, such as who knew the team, who was approached and who failed to report it.
What happens after an alert
An alert starts an inquiry, nothing more. The sport or the intelligence unit gathers betting records, account details and sometimes phone data, then decides whether there is a case. McKinstry’s failure to hand over his phone records formed part of the case against him, which shows how much investigators rely on that material.
Some alerts lead to sporting charges, some to criminal ones and many to nothing at all. The snooker case that ended with lifetime bans for Liang Wenbo and Li Hang in June 2023 was first flagged by Sportradar and then by IBIA in 2022. Lucas Paquetá’s case shows the opposite outcome, with the four spot-fixing charges against him found not proven.
The Gambling Act 2005 cheating offence sits at the far end of this process. Prosecutions under it are rare, and the regulator has said integrity cases are more often pursued as bribery, fraud or conspiracy. Our overview of insider betting law sets out the offence and the FA rules in full.
Time is the other variable. Several football cases on our timeline were sanctioned years after the bets, because account histories stay on record and can be examined later. Ivan Toney’s charges covered bets from February 2017 to January 2021. A suspicious betting report today may therefore end up concerning activity that finished long before anyone looked.
What suspicious betting checks mean for you
For most customers these systems run unseen. You may notice them only when a market is suspended early, a stake is cut back on a niche bet, or a bet is voided under the bookmaker’s terms. Bookmaker terms commonly allow an operator to void bets linked to suspected manipulation or fraud, so read that section before betting on small markets.
An account review is not an accusation. Licensed bookmakers carry out checks for many reasons, from identity verification to the financial vulnerability checks in force since August 2024. An integrity concern is one possible trigger, and ordinary betting will usually see the review end without action. Keep your account details accurate, and never let someone else bet through it.
Commercial restrictions are a separate matter. The Gambling Commission found that 4.31% of active accounts in 2024 carried some restriction, mostly stake factoring, and says no universal service obligation applies to gambling, so a bookmaker does not have to accept a bet. That is about profitable customers. It has nothing to do with integrity reporting, though both can feel the same from the outside.
If a bet is voided or an account limited and you think the decision is wrong, the route is set by licence conditions. Complain to the bookmaker first. If it is not resolved within eight weeks you can take it to the operator’s dispute service, such as IBAS, and that service must be free to use.
One last practical point. If betting on niche markets has started to feel like something you need to do, rather than something you enjoy, the tools that exist for safer gambling apply here too. Deposit limits and time-outs sit in your account settings, and a GamStop registration excludes you from every GB-licensed online bookmaker at once.
Frequently asked questions
What is suspicious betting?
It is betting activity that suggests a bettor has inside information or that an event has been manipulated, for example a cluster of new accounts backing an unlikely outcome. Bookmakers and integrity bodies treat it as a reason to look closer, not as proof of wrongdoing.
Who do bookmakers report suspicious betting to?
In Great Britain they report to the Sports Betting Intelligence Unit at the Gambling Commission, and often to the governing body of the sport concerned. Many operators also feed alerts into the International Betting Integrity Association's monitoring system.
How many suspicious betting reports does the Gambling Commission receive?
Its Sports Betting Intelligence Unit received 587 unusual or suspicious betting reports in the 2025-26 financial year, up from 501 the year before. In the quarter from April to June 2026 it received 132.
What is IBIA?
The International Betting Integrity Association is an operator-run body that monitors betting for signs of corruption. It reported 300 suspicious betting alerts in 2025, the highest on its record, with football and tennis the two largest sports.
What is Sportradar's fraud detection system?
The Universal Fraud Detection System monitors betting on sporting events for irregular patterns. In 2025 it covered over a million events across 70 sports and identified 1,116 suspicious matches, of which 618 were football.
Can a bookmaker void my bet if the betting looks suspicious?
Bookmakers' terms and conditions usually allow them to void bets connected to suspected fraud, manipulation or a breach of their rules, so check the terms of your own account. If you disagree with a decision, complain to the bookmaker first and then to its independent dispute service if it is not resolved within eight weeks.
Does an account review mean I am suspected of something?
Not necessarily. Operators review accounts for many reasons, including identity and financial checks required by their licence. An integrity concern is only one of them, and most reviews end without any further action.
Is an account restriction the same as a suspicious betting flag?
No. Stake limits on winning customers are commercial decisions, and the Gambling Commission says no universal service obligation applies to gambling, so a bookmaker does not have to accept a bet. Integrity reporting is a separate process aimed at corruption and misuse of inside information.
Which sports produce the most suspicious betting alerts?
Football leads every measure in the figures. IBIA counted 110 football alerts out of 300 in 2025, followed by tennis on 74, and the Gambling Commission says football and tennis generate the largest share of its reports.