The amount of the deposit, its refund timeline, and permissible deduction scenarios must be specified in the contract

Cost: No monetary cost. It only requires an extra ten minutes when signing the contract. The challenge lies in bringing this up in front of the landlord.
In plain terms: The deposit amount, when it will be returned, and under what circumstances deductions are allowed must all be written into the contract before you sign it. Any deduction reasons not explicitly stated in the contract cannot be used by the landlord to withhold your deposit at the end of the lease.
Benefit: Regulatory statutes make this clear: “Landlords collecting a deposit must specify the deposit amount, refund timing, and permissible deduction scenarios in the housing lease agreement. Apart from these agreed terms, landlords have no right to deduct funds without valid justification.” In short, three key points must appear in the contract: how much the deposit is, when it’s returned, and under what conditions it can be deducted. Reasons not listed in the contract cannot be used to justify any deductions.
Evidence grade: A
Sources:国务院 (2025). 住房租赁条例（国令第 812 号，2025 年 9 月 15 日施行）（第十条）. https://www.gov.cn/zhengce/zhengceku/202507/content_7032956.htm
Notes: On the day of moving out, take photos and videos together with the landlord. Capture readings from water, electricity, and gas meters, as well as images of walls and floors. If your deposit is deducted without cause, first file a complaint with the housing regulatory authority. For smaller amounts, consider pursuing a small claims lawsuit — see Section 8 for details.