Sports Betting Taxes Commercial Content. Play Responsibly. 21+ As summer winds down and we get closer to tax season, it’s important to keep sports betting taxes in mind. Any bet winnings no matter how small are subject to a gambling tax and rules can vary by state. While that may seem overwhelming, we’re here to simplify NJ sports betting taxes for you. And don’t miss our other essential betting guides. Are Sports Betting Taxes a Thing? NJ online sports betting has become a popular industry.