How long must employees pay social security when they join the company?

Within thirty days. It is illegal for a company to apply for social insurance for its employees within 30 days from the date of employment, and not to buy insurance during the probation period or within one month. Social security refers to the principle that the state raises funds through various channels through legislation according to the correspondence between rights and obligations, and provides material help to the insured when he is faced with risks such as old age, illness, work injury, unemployment and maternity.