A robber posed as a UPS worker to pull off an armed home invasion that netted more than $40,000 in Harlem, police said today.

The suspect sported a brown vest and button-down shirt, as well as a brown knit hat, and knocked on the victim’s apartment door near 133rd Street about 10:30 a.m. March 11, cops said.

When a resident opened the door, he and an accomplice flashed a gun and forced their way in.

The duo tied up three people inside and took $28,000 from their safe, police sources said. They also took $12,000 from a dresser and $500 from one victim’s pants pocket, sources added.

The crooks fled in a silver Nissan Quest. Both suspects are in their 20s and between 5-foot-10 and 6 feet tall, cops said.

The accomplice wore gray sweats and a baseball hat with a gray brim and carried a black backpack.

Anyone with information should call Crime Stoppers at 1.800.577.TIPS (8477), or log onto the Crime Stoppers’ Web site at www.nypdcrimestoppers.com.