Join the company on the 25th, and pay the social security for that month?

Of course. Because the deadline for paying social security every month is 25th, if you join the company after 25th, the company will pay social security next month. If you don't pay medical insurance for one month, your personal account will not be cleared, but your public account will be recalculated. That is, the maximum reimbursement amount is recalculated.

Social insurance refers to the system that the state establishes a social insurance fund through legislation to give necessary material help to workers who participate in labor relations when they lose their ability to work or are unemployed. Social insurance is not for profit.

According to the regulations, the employer shall register social insurance for employees within 30 days from the date of employment. If the social insurance has not been registered, the social insurance agency shall verify the social insurance premium it should pay.

If you continue to pay the local prescribed number of years (not invalidated midway), you can continue to enjoy medical insurance after retirement without paying. So it should be possible not to make up for it in less than one month, but if you don't make up for it for three consecutive months, you will have to reapply.

Legal basis:

People's Republic of China (PRC) social insurance law

Article 58

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. If the social insurance has not been registered, the social insurance agency shall verify the social insurance premium it should pay.

Employees-free individual industrial and commercial households who voluntarily participate in social insurance, part-time employees who do not participate in social insurance in the employing unit and other flexible employees shall apply to the social insurance agency for social insurance registration.

The state establishes a national unified personal social security number. Personal social security number is a citizen's identity number.