FedEx and UPS have racked up a combined $2.8 million in city parking tickets in just the first three months of this year.

They and other commercial delivery companies account for 20 percent to 30 percent of the roughly 10 million parking tickets that get dished out annually in the Big Apple, according to Crain’s New York Business.

The two delivery giants are among the biggest gold mines for the city, which expects to collect $550 million off parking violations this year. Others left with big illegal-parking tabs include Verizon, the US Postal Service and Time Warner.

“If we have to double-park, then yes, we will,” a UPS spokesman said. “It’s the cost of doing business.”

No one is happy about the situation except the city’s bean counters. Some of the businesses have sued over alleged ticket blitzes.

Meanwhile, transportation advocates have ripped ticket discounts that some companies get through a city Finance Department program aimed at speeding up payments, alleging to Crain’s that it worsens congestion.

“You have big delivery companies writing the [cost of] tickets into their business plans,” said Paul Steely White of Transportation Alternatives.

“Getting a discount on a parking ticket just exacerbates the problem of congestion. They’ll just park there all day long.”