Is it legal to withdraw rent at will and overcharge 15 days?

It depends on how the contract is agreed. If it is not handled according to the contract, it can be brought to court. How to guarantee the refund of the deposit: (1) Both parties shall settle it through consultation. When signing the lease contract, both parties shall indicate how many working days after the lease expires. If the house and its facilities are not damaged, the owner shall refund the deposit. (2) According to the nature of the deposit, if the goods are kept safely, they can be returned, but if the agreement is liquidated damages, they cannot be returned. The rent can be settled by both parties through consultation or deducted. Check out one month in advance in writing. (3) Both parties sign a house lease contract. With the lease agreement, it is necessary to strictly implement the agreement. For the payment of rent, it is also necessary to implement the contract. If there is no agreement, it can be supplemented through consultation. In addition, if the other party refuses to rent, it is a breach of contract, and you can ask the other party to bear the liquidated damages and compensate the actual losses. If negotiation with the other party fails, you can bring a lawsuit to the court.

Legal basis:

Article 54 of the People's Republic of China (PRC) Urban Real Estate Management Law, the lessor and the lessee shall sign a written lease contract, stipulating the lease term, lease purpose, lease price, repair responsibility and other rights and obligations of both parties, and register with the real estate management department.