Delaware just started sports betting. What you should know

  • The First State, which already had allowed multigame bets on professional football, will now let gamblers bet on single games for a variety of professional sports.
  • If you win more than $5,000 from gambling, you can generally expect the payer (i.e., the casino) to withhold 24 percent for taxes.

If you plan to head to Delaware on Tuesday to take advantage of its opening day for legalized sports betting, don't forget your winnings won't be all yours.

The IRS will want a piece of the action.

"The amount of gambling winnings, less any losses, gets tacked on to all other income you have … and is taxed as ordinary income," said Bill Smith, managing director at CBIZ MHM's National Tax Office in Washington.

NFL playoff games joins horse racing in being legalized for wagering in the state of Delaware and gamblers took advantage of it at Delaware Park
Algerina Perna | Baltimore Sun | MCT | Getty Images

Delaware's legal sports wagering kicks off at 1:30 p.m. ET on Tuesday at the state's three casinos: Delaware Park, Dover Downs Hotel & Casino and Harrington Raceway & Casino.

The move comes just three weeks after the U.S. Supreme Court struck down a 1992 federal law that banned sports betting in states that didn't already have a law on the books. Delaware already had a partial exemption to the law and offered parlay betting — multigame bets — on pro football.

Now, however, gamblers there will be permitted to bet on single games and championships for a variety of professional sports, including baseball, football, hockey, basketball, soccer, golf and auto racing, according to the governor's office.

While this is typically a slower time of year for sports betting, gamblers will be able to wager on the NBA championship series and the Stanley Cup hockey finals, both of which are under way.

The "First State" is beating its peers to the punch on rolling out sports betting, basically because it already had the legal and regulatory structure in place. Lawmakers in New Jersey — which had challenged the federal law banning it — are expected to consider legislation this week that would regulate such wagering.

Other states moving toward offering it include Pennsylvania, West Virginia and Mississippi. The old law, the Professional and Amateur Sports Protection Act, largely outlawed sports betting outside of Nevada.

As for taxation of your winnings: The new tax law that took effect this year continues to allow winners to deduct their gambling losses up to the amount of gambling income, as long as they itemize their deductions instead of taking the standard deduction. The information gets reported on your Form 1040 as "other income."

Be aware that because the standard deduction nearly doubled for all taxpayers and most deductions were eliminated, fewer taxpayers are expected to have enough deductions to make itemizing worth it.

Professional gamblers, meanwhile, face other rules for 2018 through 2025: When they deduct their expenses (i.e., traveling to and from a casino), they must add them to their gambling losses when calculating the value of the deduction instead of writing them off separately as a business expense.

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Generally speaking, if your winnings are above $5,000, the payer, such as a casino, is required to withhold federal taxes. Effective this year, that withholding rate is 24 percent, down from the previous 25 percent.

However, don't assume the amount withheld is what you'll actually owe on the money.

"The casino doesn't know if you make $12,000 a year or $26 million a year," Smith said. "They withhold at that rate, but they don't know what tax bracket you'll be in."

Taxes also might be withheld on winnings of less than $5,000 in certain situations, such as if the amount won is 300 times the original bet (i.e., a $600 win on a $2 bet).

Additionally, depending on how much you win, you'll receive a Form W-2G from the casino. Even if you do not, the IRS still expects you to pony up at tax time.