Factors do consider your financial standing when making funding decisions, but they do not rely solely on your credit standing.
They also weigh the credit of your customers and their ability to pay on open accounts. After all, the factor's primary means of repayment is your customer, not you. Hence, credit blemishes that might disqualify you from other forms of finance may be acceptable to a factor.
This component of factoring makes it a viable solution if your business is too new to have solid credit, or your credit has slipped due to unforeseeable circumstances.