A person has three social security numbers.

1. One ID number corresponds to one person, and only one social security computer number can be processed.

2. When a person is employed in different units, the unit enrollment information number under the social security computer number is different.

3. No matter whether you are insured in your domicile or in a non-domicile place to pay social security, you can eventually move the social security accounts insured in various places back to your domicile place to merge, without affecting your accumulated payment period.

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