Is it legal to install billboards in residential elevators?

Illegal. If the property company uses the elevator to advertise without authorization, it may be punished in violation of the relevant provisions of the Property Management Regulations. Legal basis: Article 54 of the Regulations on Property Management, if a property uses * * * parts and * * * facilities and equipment for business operation, it shall go through relevant procedures in accordance with regulations after obtaining the consent of relevant owners, owners' congress and property service enterprises. Owners' income should be mainly used to supplement special maintenance funds, and can also be used according to the decision of the owners' congress. Sixty-third in violation of the provisions of this Ordinance, one of the following acts, the real estate administrative department of the local people's government at or above the county level shall order it to make corrections within a time limit, give a warning, and impose a fine in accordance with the provisions of the second paragraph of this article; The proceeds will be used for the maintenance of * * * parts and * * * facilities in the property management area, and the rest will be used according to the decision of the owners' meeting: (1) changing the use of planned public buildings and * * * facilities in the property management area without authorization; (two) unauthorized occupation and excavation of roads and sites within the property management area, which harms the interests of the owners; (three) unauthorized use of property * * * with parts, * * with facilities and equipment for business. Individuals who commit one of the acts listed in the preceding paragraph shall be fined 1000 yuan or more and 10000 yuan or less; If a unit commits one of the acts listed in the preceding paragraph, it shall be fined between 50,000 yuan and 200,000 yuan.