How many keys are there on the door of a building? Because there were not enough keys, I couldn't find them, and I forgot how much the property gave at that time.

Generally speaking, today's security doors are equipped with two renovation keys and four official keys. We are generally divided into A\B keys. When decorating, we use a key to facilitate the staff of the decoration company to open the door when decorating. After the renovation, we use the B key, and the A key will be invalid. After that, we can always use the B key.