Creditworthiness refers to the solvency of a person with legal capacity. People with a high income enjoy a good credit rating because they are solvent and "creditworthy".
The credit rating is calculated from various factors. To assess and classify the debtor to be rated, the rating agencies, banks and financial service providers collect the published data, contact the debtor for additional information and evaluate this data (scores for private individuals or ratings for companies) internally. A distinction is made between quantitative and qualitative factors.
Quantitative factors are the assessment of economic circumstances such as income, loans, real estate, etc.. Qualitative factors include education, future forecasts and behavioral patterns (were contracts honored, were interest and principal payments serviced on time).