Can I buy social security for myself at the age of 40?

At the age of 40, both men and women can pay personal social security. When a woman reaches the retirement age of 50 and fails to pay social security for 15 years, she can go through retirement procedures first, and then go through retirement procedures. Men from 40 to retirement age who have paid social security for 15 years can go through retirement formalities directly.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.