Is there a formula banks and other creditors use for new credit card approval? Other than credit score of course. For example for a business credit card I imagine it would be something considering assets, liabilities and revenues.
Banks use quite a few parameters to arrive at the decision for card approval. The credit score is just one input. There are multiple other inputs it would source, for example total years in job, the number of years in current job, income streams, etc ... the exact formula is a trade secret and varies from Bank to Bank
Three big ones that are common in almost all banks (though, individually, they may have other criteria):
- Annual/Monthly income.
- Debt to income ratio.
- Length of credit history.
Other criteria I've seen (while working in the banking industry - varying by bank): the average balance you keep on deposit accounts (checking/savings/CDs/etc), number of overdraft fees in the past 12 months (one bank I worked for wouldn't approve a credit card if a customer had more than 5 overdrafts in the past year), the length of time a customer had been with the bank.
Note that a credit card only company, like AmEx, may have different criteria in that they don't offer all the other type of accounts that other other banks do.
Bigger than the three mentioned above is on-time payment and/or collections activity. If your report shows you have not paid accounts on time, or have accounts in collections, that is almost guaranteed decline except for the least desirable cards.
Another factor is number of hard inquiries. If you have been on a recent application spree, you will get declined for too many recent inquiries. Wait 12-18 months for the inquiries to roll off your report.
Applications for business cards are a little tricky depending on whether you are applying as an individual or as an employee of a corporation. I usually stay away from these as you can be liable for company debts you did not charge under the right circumstances.