legal ground
Article 585 of the Civil Code
The parties may agree that when one party breaches the contract, it shall pay a certain amount of liquidated damages to the other party according to the situation of breach of contract, and may also agree on the calculation method of the amount of compensation for breach of contract.
If the agreed liquidated damages are lower than the losses caused, the people's court or arbitration institution may increase the liquidated damages at the request of the parties; If the agreed liquidated damages are excessively higher than the losses caused, the people's court or arbitration institution may appropriately reduce them at the request of the parties.
Article 12 of the Interpretation of the Supreme People's Court on Several Issues Concerning the Application of Law in the Trial of Disputes over Commercial Housing Sales Contracts.
If the parties demand a reduction on the grounds that the agreed liquidated damages are too high, they shall reduce them appropriately on the basis that the liquidated damages exceed 30% of the losses caused; If the parties demand an increase on the grounds that the agreed liquidated damages are lower than the losses caused, the amount of liquidated damages shall be determined according to the losses caused by the breach of contract.