I don't know exactly what "credit system" means here, but the only difference I see is that certain types of lending are so low risk or low amount, that lenders find it possible to automate the job via the use of the credit reporting agencies, who (in the US) use social security numbers to summarize people's history of repaying debts.

For any sufficiently large transaction, even for a person, such as a home mortgage, there will be manual review of people's incomes and assets, just like there is for businesses.