Do I need to file a labor contract to buy social security?

The failure to file the labor contract does not affect the payment of social security. As long as both parties sign labor contracts and establish labor relations, they must pay social security. 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. The employing unit shall conclude a written labor contract when establishing labor relations with laborers from the date of employment.