You could offer to consult with them to help them improve their credit rating which will increase their ability to get loans at better prices.

Depending on the nature of the business, factoring may be an option.

If your client has a FICO below 700, lending can be more challenging. SBA and Conventional Loans may not be easy to get. If you want to pursue this option, you will want to work with a business loan broker to help spread your risk and be more efficient. If this option is not fruitful, alternatives include the following:
1. Portfolio loan/Margin loan off of non-retirement brokerage funds. FICO is not relevant for these loans. I know of an option that allows a client to take between 65% to 85% of the funds they have in the market. The amount and rate are dependent on the risk of the portfolio.
2. Rollover for Business Startup Program: You can use qualified retirement funds tax and penalty free and invest this into a private business. This 46 year old program was blessed by the IRS and does not care about FICO credit either.
3. Peer-to-Peer lending groups or private loans.
4. Commercial Capital Training Group: Alternative financing options here to include Money Factoring, Hedge Fund Loans, and other Specialty and Alternative Funding options.