How should property companies choose elevator maintenance units?

Elevator maintenance is the maintenance content implemented from the end of the free maintenance period of the elevator installation unit. Choosing the maintenance unit is directly related to the accident frequency and service life of the elevator. I suggest you go to the technical supervision bureau or the special equipment and facilities administration to verify the qualified maintenance units, and then invite tenders. Don't believe in promises without business license and legal person qualification. If there is a safety accident, the loss will be unbearable.