Grubhub might have to swallow hard when it reads this new set of rules.

The New York State Liquor Authority — a powerful agency that regulates restaurants serving alcohol statewide — is developing new rules that will significantly curb the stiff fees that can be charged by food-ordering companies like Grubhub, Uber Eats, DoorDash and Postmates, The Post has learned.

The SLA’s new rules could slash the fee income of Grubhub, which also owns the Seamless food-ordering site, to 10 percent of a takeout order from its current 15 percent to 30 percent, according to sources close to the situation.

Alternatively, the liquor agency could force Grubhub and others to be listed on thousands of liquor licenses, creating a potential trove of legal liabilities and bureaucratic hassles for the companies, according to sources familiar with the situation.

“We have guidance for third-party providers drafted that will be presented to the [SLA] board for their consideration in the coming weeks,” William Crowley, a spokesman for the agency, confirmed in a statement to The Post.

At issue is the agency’s existing rule stating that anyone who profits from a liquor license must be listed on the license — regardless of whether alcohol is part of a sales transaction.

The only exception to this rule is a landlord who is allowed to take up to 10 percent of a restaurant’s or bar’s profits.

“Historically, we’ve allowed landlords to include a 10 percent of revenue [clause] in their leases,” Crowley said, adding that anything above that threshold is considered profiting off of the sale of alcohol.

The New York liquor board is the latest government agency to scrutinize Grubhub’s business model — which could cost the company big bucks in its most important market.

Last month, the New York City Council grilled Grubhub executives about bogus fees it has been charging restaurants for phone calls that don’t generate food orders — a practice that was first exposed by The Post in May.

Meanwhile, the New York City Hospitality Alliance, which represents bars and restaurants in the Big Apple, testified at the June hearing that it has been pushing for the SLA to force the delivery companies into compliance with its licensing rules.

“Any person or entity that shares in the revenues of a business licensed by the SLA must be on the liquor license,” Robert Bookman, counsel to the New York City Hospitality Alliance, told The Post. “I don’t see how the agency can make an exception for these delivery companies.”

The trade group is also calling on the New York State Attorney General’s office and the federal government to investigate whether Grubhub is violating antitrust laws because of alleged monopolistic behavior. Grubhub controls 69 percent of the New York City food delivery market, while Uber Eats commands 14 percent and DoorDash has 10 percent, according to Second Measure, a firm that analyzes purchase data.

For Grubhub, being listed on the license would involve fees, a massive amount of paperwork and months of waiting for licenses to be approved.

That’s not to mention the liability associated with serving minors alcohol, liquor license attorneys said.

Grubhub didn’t respond to requests for comment.