A sportsbook is a gambling establishment that accepts bets on sporting events and pays out winning bettors. These facilities are heavily regulated in order to ensure that they treat their customers fairly and comply with laws against money laundering, underage gambling, and other criminal activities. They are also required to provide tools and support services for responsible gambling.

In the US, the majority of sports betting is done through licensed casinos and authorized operators. However, since 2018, many states have made it legal to place wagers through non-licensed operators. This has created a shadowy market of unlicensed sportsbooks, known as corner bookies or illegal operatives. These illegal businesses are largely staffed by crooks, who take advantage of the lack of regulatory oversight to commit fraud and other crimes.

To compete with these illegal operations, sportsbooks must offer their customers the same security measures that licensed casinos use. In addition, they must be able to respond quickly to customer inquiries and concerns. They must also have a good relationship with their data providers, as this is the main source of information about the events that they offer bets on.

A key mistake that many newcomers to the sportsbook industry make is using a turnkey solution for their operation. These solutions come with a variety of drawbacks, including high operational costs and low profit margins. In addition, they may not be scalable and can leave you paying more than you are earning in some months. It’s best to work with a development team that can help you build a fully customized sportsbook with all the features you need for a successful business.