The warranty period is the period during which the Contractor is responsible for the warranty of the completed project after the completion of the project. The time of warranty period is specified in the contract. The warranty period starts from the date when the Owner's Engineer issues the project completion certificate. The Contractor's tasks during the warranty period are:

(1) Complete the remaining work left at the time of issuing the project completion certificate;

(2) Complete the construction quality problems found during the use and warranty period of the project owner, and repair, modify, rebuild, correct and repair them. Make the project reach the state required by the contract and hand it over to the owner. Cost of repair work. If the materials or operation processes used in the construction do not meet the requirements of the contract, or the Contractor neglects or fails to comply with the obligations specified in the contract during the construction, the relevant costs shall be borne by the Contractor. If the Owner's Engineer considers that the necessary maintenance is due to other reasons (such as damage caused by the Owner in use), the cost shall be verified and paid by the Owner as additional work. When the warranty period of the project expires, the owner's engineer will issue a maintenance certificate after the final acceptance of the project owner. This maintenance certificate is the final acceptance certificate of the project.

Form of expression

Generally, when the consumer completes the transaction with the merchant, the merchant handles the warranty card for the consumer along with the product as the warranty voucher.

The warranty certificate will generally specify consumer information, purchase date, product model, ex factory date, warranty period and scope, maintenance records, etc. Warranty is divided into two types: warranty with a certain period of time and lifetime warranty. Products with a warranty period mainly refer to electronic and electrical products, vehicles, mechanical equipment, etc. Now powerful companies also pay more attention to the impact of after-sales service on efficiency. Products with good after-sales service include national joint insurance, multinational companies and global joint insurance services.

Construction project warranty

Article 40 of the Regulations on the Quality Control of Construction Projects of the State Council stipulates: 'Under normal use conditions, the minimum warranty period for construction projects is:

（1） Infrastructure works, foundation works of housing construction and main structure works are the reasonable service life of the project specified in the design documents;

（2） 5 years for roof waterproof works, toilets, rooms and exterior walls with waterproof requirements;

（3） The heating and cooling system includes two heating and cooling periods;

（4） 2 years for electrical pipeline, water supply and drainage pipeline, equipment installation and decoration works.

The warranty period of other projects shall be agreed between the Employer and the Contractor. The warranty period of the construction project shall be calculated from the date of passing the completion acceptance. '