Police say the man broke into the office on the 1700 block of East Moyamensing Avenue early Sunday morning.
Officials say the thief stole checks, computers, a credit card reader and mail.
The suspect has a tattoo on the back of his neck.
Anyone with information is asked to contact Philadelphia Police at 215-686-TIPS (8477), text a tip to PPD TIP (773847) or through PhillyPolice.com.
