Texas gambling winnings are included in the 'other income' section of your 1040 tax return. It is necessary to report all winnings when you file your taxes. Yes, gambling winnings in the state can be taxed even if you have used a Texas sports betting promo code. Keep reading to learn more about the specific rules surrounding the Texas gambling tax. Texas residents with significant earnings from gambling are usually subject to a 24% flat rate tax on winnings. The amount of gambling tax in Texas that you owe will largely depend on if you are above a certain winnings threshold. Use our Gambling Tax Calculator Texas to figure out how much you might owe from gambling in Texas. Luckily, we've made calculating your taxes on gambling in Texas easy.