He flashed a handgun, stole cash from the register and then fled the scene on foot, police said.
Nassau County police are searching for the suspect they said robbed Millennium Tax Service on Nassau Road in Roosevelt at about 7:45 p.m. Tuesday.
Police said the suspect, wearing a dark-blue hooded sweatshirt, black-and-white sneakers and a backpack, entered the business, “displayed a black handgun to an employee” — and demanded cash. Police did not disclose how much was taken.
The suspect was last seen fleeing west on Woods Avenue, police said. No one was injured.
Anyone with information about the robbery is asked to call Crime Stoppers at 800-244-8477. All calls will remain confidential.