Can Tianjin and Beijing pay social security at the same time?

Tianjin and Beijing cannot apply for social security at the same time, because the ID card and social security number remain unchanged. First, if you have insured in two provinces at the same time, you can merge in the social security where your household registration is located, but it is more cost-effective for you to adjust the insurance base. Second, social insurance is a kind of insurance required by the state. The state develops social insurance undertakings, establishes a social insurance system and sets up a social insurance fund, with the aim of enabling workers to get help and enjoy insurance benefits in old age, illness, work injury, unemployment and childbirth. China's "Labor Law" and "Social Insurance Law" clearly stipulate that it is the legal obligation of the employer to pay social insurance for workers, which is obviously compulsory by the state, and the employer shall not refuse to undertake this legal obligation under any excuse or reason.