Find the number of the local housing authority where the rental violation is, and call and report it.
Submit your complaint to the housing authority in detail. Specifiy what codes are being violated and the rental unit that is in violation.
Follow up with the housing authority in a week to make sure that the complaint was taken care of.
If the local housing authority has not taken care of the violation expeditiously, then you can contact your state HUD office.
Go to the U.S. Department of Housing and Urban Development's website, and look up your state's contact information. You can also call a toll-free number, which is the Multifamily Housing Complaint Line.
Submit your complaint to HUD via phone, email, mail or fax. If you want to remain confidential and anonymous, calling the toll-free number would be the best route. Going through their online system is not secure, and could be read by someone else. After submitting your complaint, you can rest assured that the code violation will be handled. The federal government is very serious about rental properties being misused or not properly taken care of, because that is a mishandling of their money.