With the new Republican tax law set to put a cap of $10,000 on federal property tax deductions for 2018, New York taxpayers are scrambling this week to figure out if they can prepay and take their deduction before year’s end.

Next year’s property taxes can be prepaid in New York City, and so can those for Rockland County. But if you live in Westchester, you may be out of luck unless your individual town or city has already billed the tax and will accept early payments.

Confusion cranked up last Friday when an executive order from Gov. Cuomo paved the way for some— but not all — of the taxing jurisdictions in New York state to accept early payments.

“The governor recognized some people could benefit from this executive order,” said Ken Wray, mayor of Sleepy Hollow, which can’t process early payments because its fiscal year ends June 1. “For us, it’s not applicable.”

The Internal Revenue Service on Wednesday said it will allow a deduction this year for the payment of 2018 taxes only if they already have been assessed. But it won’t allow a deduction if a county, for instance, merely changed its computers to accept an early payment.

While Cuomo’s order speeds up the issuance of a “tax warrant” to allow prepayments, it doesn’t eliminate the legal process, or any of the steps that come before it, including the adoption of a budget. The order also required that the warrant be issued before midnight on Thursday.

“It is just not possible,” said Ned McCormack, Senior Advisor to Westchester County’s Executive, who said in a statement that given just four days, the county could not issue the documents needed “for a whole host of legal, operational and practical reasons.” Its fiscal year doesn’t start until July 1.

Rockland County, however, with a Jan. 1 fiscal year, already had all its budget ducks in a row. Its legislature was set to vote for the needed warrant on Wednesday.

Unless a part payment is due in January, most school taxes in New York State aren’t billed until the fall and also can’t be prepaid.

This is not the first time officials and taxpayers have had this conundrum. In December 1985, facing changes from President Reagan’s tax plan, the New York State Comptroller’s office sent a letter to Clarkstown officials advising they could collect the voluntary payment of taxes early, but only if the warrant was issued.

“It’s all the same legal principles that apply today,” said Peter Baynes, executive director of the NYS Conference of Mayors.

New York City’s full year bills are set and sent out in June for the fiscal year that begins July 1. Most homeowners pay on a quarterly basis and the city will accept early payments for any bills already due in 2018.

The city’s 311 service received 926 calls about prepayments last Friday and another 2,100 calls on Tuesday. This time last year, the city averaged 362 calls about prepayments per day.

Additional reporting by Yoav Gonen