Once a mistake is reported, the bureau has 30 days to investigate and respond. If the information you are challenging is determined accurate, it will remain in your credit file. If the information is not accurate, it should be removed from the report. You may be turned down for credit because you haven't been at your current address or job long enough. It may be that your income doesn't meet the lender's criteria.
Different creditors have different standards.
An inquiry is a record placed in your file each time someone checks your credit report. Too many recent inquiries are a red flag to potential lenders. This is because they fear you may be jeopardizing your ability to repay debts by taking out too many loans. Even if you have not been denied credit, you may wish to find out what is in your credit file. This is especially important if you are planning to make a major purchase such as a vehicle or home.