Sportsbook software is the system that a bookmaker runs on. It has a betting engine that accepts and records each bet, a pricing system that sets the odds from live match data, and risk tools that limit what the bookmaker could lose. A bookmaker, also called a sportsbook, is a company that takes bets on the results of sports matches and pays the winners. Some bookmakers build their own software. Many others rent it from a specialist supplier.
Odds tell the bettor how much a winning bet pays. In Britain and the rest of Europe, odds are often written as decimal odds. A £10 bet at odds of 2.50 returns £25 if it wins: the £10 stake back, plus £15 of winnings. Odds also show the chance that the bookmaker gives a result. Odds of 2.50 mean a chance of 1 in 2.5, or 40%.
Say a bettor in Leeds, in Britain, wants to bet £10 on a football team to win, at odds of 2.50. When he taps the button, the betting engine runs several checks within about a second. It checks that his account holds £10. It checks that the odds have not changed since his screen showed them. It checks that the bet stays within the limits set for his account and for that result. Then it records the bet, deducts £10 from his balance and confirms the bet on his screen. After the match, the engine settles every bet on that result. It pays each winning bet and closes each losing one.
The odds come from the pricing system, which is described in in-play odds. It uses live sports data from the ground. The limits come from sportsbook risk management.
How does the bookmaker earn? It sets its odds so that the chances of all the results add up to slightly more than 100%. For a match with two possible results, it may offer odds of 1.90 on each. Each of those odds means a chance of 52.6%, so together they add up to 105.3%. As a result, across many bets, the bookmaker pays out a little less than it takes in. This is the bookmaker's form of the house edge.
Before anyone may bet, the bookmaker must confirm the person's identity and age, through identity verification (IDV). Deposits arrive through a payment gateway. The bookmaker must also watch for problem gambling, under the rules of responsible gambling. It passes unusual deposits and bets to AML transaction monitoring.
Betting on sport online is illegal in India, and the Online Gaming Act 2025 banned every online game played for money. But engineers in Hyderabad, Pune and Bengaluru build the betting platforms that British and European bookmakers run on. One British betting group runs its main technology centre in India.