Many municipalities and counties have implemented ordinances requiring property owners to standardize the display of house numbers on buildings. The city of St. Martinville, Louisiana, for instance, is considering requiring its citizens to display street numbers in block numbering that is at least 4 inches tall and is either illuminated at night or has a reflective finish. If the ordinance is passed, the city will fine offenders $200, plus hundreds more in court fees. In Florida, the cities of Clearwater, Largo and St. Petersburg have begun enforcing their own municipal codes that regulate the visibility of house numbers, imposing fines for violators.

Inspect the address or street number to determine that it is visible from the street with numbers in contrast to their background.

• The numbers assigned to houses by the municipality occasionally change, and homeowners must adjust their house numbers accordingly.
• The trees or shrubs in front of the house have grown so much that the number is no longer visible. House numbers installed in the winter may be visible during that season but become blocked by budding vegetation by spring or summer.
• House numbers will require maintenance when they get dirty. Numbers may not be reflective or contrasting if they are covered in mud.  
• Snow piles created by snow plows during the winter may be high enough to cover the number. If this happens, the number should be raised so this situation does not repeat.