1, the proof of work need to be stamped with the company seal or not valid, private enterprises do not have a business license, naturally, there will be no company seal.

2, private enterprise without a business license is not allowed to recruit employees, if the business will be found to be fined, if fined, employees will not get a salary, then can not be opened to the income certificate, in this kind of business work is not guaranteed, it is recommended to look for a new job.

3, the essence of the proof of work is the enterprise guarantee, there is no official seal can not prove that the work situation, what evidence is not naturally have the qualification of guarantee.

4, proof of work refers to the citizens of China in the daily production and life and business activities, the need for bank loans or credit card applications and other daily production and life and business activities, proof of work is also known as proof of employment, the format by the required proof of the unit's issuance, the issuance of proof of the individual only need to fill in the proof of personal information and stamped with the official seal of the unit can be.

Individual households include the following:

1, in accordance with the provisions of the administrative organs for industry and commerce at all levels of registration, to receive the "business license" of individual business households. Specifically, it refers to individual workers who are engaged in activities such as industry, commerce, construction, transportation, catering and service, etc. within the scope permitted by law and approved for registration according to the law;

2. In accordance with the "Interim Regulations on the Registration and Administration of Privately-run Non-Enterprise Units", approved for registration by the civil affairs departments of the State Council and the people's governments of the localities at and above the county level and receiving the "Certificate for the Registration of Privately-run Non-Enterprise Units Or "private non-enterprise unit registration certificate" of the private non-enterprise units;

3, did not receive a "business license" but actually engaged in self-employment activities in urban and rural self-employment units. However, it does not include some part-time industrial, commercial and other activities carried out by peasant families with auxiliary labor or using their leisure time.

Legal basis:

The Social Insurance Law of the People's Republic of China

Article 57

An employing unit shall, within thirty days from the date of its establishment, with its business license, certificate of registration, or seal of the unit, apply for registration of social insurance with the local social insurance agency. The social insurance agency shall examine and approve the application within fifteen days from the date of receipt of the application and issue the social insurance registration document.

If the employer's social insurance registration changes or the employer is terminated according to law, the employer shall, within thirty days from the date of change or termination, apply to the social insurance agency for change or cancellation of social insurance registration.

The market supervision and management department, the civil affairs department and the organization and establishment management organs shall promptly notify the social insurance agency of the establishment and termination of the employer, and the public security organs shall promptly notify the social insurance agency of births and deaths, as well as the registration, relocation, and cancellation of household registration of individuals.