Beijing social security and Tianjin social security can apply at the same time.

Legal analysis: Tianjin and Beijing cannot apply for social security at the same time, because the ID card and social security number remain unchanged.

Legal basis: People's Republic of China (PRC) Social Insurance Law.

Article 4 Employers and individuals who pay social insurance premiums according to law in People's Republic of China (PRC) have the right to inquire about payment records and personal rights and interests records, and ask social insurance agencies to provide social insurance consultation and other related services. Individuals enjoy social insurance benefits according to law and have the right to supervise the payment of their own units.

Eighth social insurance agencies to provide social insurance services, responsible for social insurance registration, personal rights and interests records, social insurance benefits payment and other work.