Group 1 - The duration of the probation period is regulated by the Labor Contract Law, with specific limits based on the length of the labor contract [4][5][6][7] - For contracts longer than three years, the probation period can be up to six months, while for contracts of one year to less than three years, it is limited to two months [6][7] - A probation period can only be agreed upon once between the same employer and employee, and it must be included within the labor contract duration [7] Group 2 - It is mandatory to sign a written labor contract upon establishing a labor relationship, which begins from the date of employment [11][12] - If a written labor contract is not signed within one month of employment, the employer must pay the employee double the salary for each month until the contract is signed [11] Group 3 - During the probation period, the salary must not be lower than 80% of the agreed salary or the minimum wage for the same position in the company [14] - The salary during the probation period must also meet or exceed the local minimum wage standard [14] Group 4 - Both the employer and employee are legally required to participate in social insurance and pay social insurance fees, even during the probation period [18][19] - The employer must register for social insurance within 30 days of employment [16][17]

Core Viewpoint - The article emphasizes that employers are legally required to register employees for social insurance and pay social insurance fees from the first day of employment, including during the probation period [3][4][5]. Group 1: Social Insurance Obligations - Employers must apply for social insurance registration within 30 days from the start of employment [3]. - Both employers and employees are legally obligated to participate in social insurance and pay the corresponding fees, which is a mandatory requirement [4]. - Even if there is mutual agreement between the employer and employee, social insurance fees cannot be waived during the probation period [5]. Group 2: Resignation and Penalties - According to the Labor Contract Law, employers cannot impose penalties on employees for resigning during the probation period unless specified conditions are met [9][10]. - Employees are generally not required to pay penalties to employers for resigning due to personal reasons, except in specific legal circumstances [10].