Is it legal for the company to pay only the housing accumulation fund to employees and not social security?

Companies can't just pay employees housing provident fund without paying social security. If the employer fails to apply for social insurance registration, the social insurance administrative department shall order it to make corrections within a time limit; If no correction is made within the time limit, a fine shall be imposed. The employing unit shall, within 30 days from the date of employment, apply to the social insurance agency for social insurance registration for its employees.

legal ground

Article 84 of the Social Insurance Law of People's Republic of China (PRC)

If the employer fails to apply for social insurance registration, the social insurance administrative department shall order it to make corrections within a time limit; If no correction is made within the time limit, the employer shall be fined between one and three times the amount of social insurance premiums payable, and the directly responsible person in charge and other directly responsible personnel shall be fined between 500 yuan and 3,000 yuan.