How to do social security without a company in Beijing? Foreigners

No difference, the process results are the same.

Social security currently does not have a national network, you can only 'start paying social security' in Beijing, there is no question of re-doing it or transferring it.

As for the social security of foreign countries, you can choose to apply for social security transfer, or you can do it again before retirement. At present, social security transfer processing is very convenient, submit an application in the new payment place can be.