Is it legal to install a credit card device on the elevator?

Illegal, this behavior is only made unilaterally by the property, because the cost of these public facilities has been included when buying a house, elevators belong to public facilities, and it is illegal for the property to do so.

Legal basis:

property management regulations

Article 35 A realty service enterprise shall provide corresponding services in accordance with the stipulations of the realty service contract. The realty service enterprise fails to perform the realty service contract, causing personal and property safety damage to the owner, and shall bear corresponding legal responsibilities according to law.

Thirty-sixth property services companies to undertake the property, it shall go through the formalities of property acceptance with the owners' committee, the owners' committee shall hand over the materials stipulated in the first paragraph of Article 29 of these regulations to the property services companies.

Article 56 If, in violation of the provisions of this Ordinance, a residential property construction unit fails to select a property service enterprise through bidding or selects a property management service enterprise through agreement without approval, 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 it a warning and may concurrently impose a fine of more than 6,543,800 yuan.