This thread is very relevant to me right now. We used invoice factoring for about 18 months and just exited the arrangement. A few things I learned the hard way that might help others:
The UCC filing is the big one. When you sign a factoring agreement, the factor files a UCC-1 financing statement against your business. This is a public lien on your receivables. Even after you repay or terminate the agreement, that UCC filing stays on record unless the factor files a termination statement. If they do not file it, it shows up when banks or other lenders run credit checks on your business and can block you from getting a line of credit or SBA loan.
Demand a UCC termination in writing as part of your exit. Do not assume they will do it automatically. In our case, the factor dragged their feet for 3 months after we paid off the final advance. I had to send a formal demand citing UCC Section 9-513, which requires the secured party to file a termination statement within 20 days of receiving an authenticated demand. They filed it within a week after that letter.
Client relationship damage is real. Two of our best clients told us they were uncomfortable receiving collection notices from the factoring company. One client actually withheld payment on a subsequent invoice because they were confused about who to pay. If you are in a relationship-driven business, think carefully about whether factoring is worth the risk to those relationships.
My recommendation for anyone considering factoring: explore SBA microloans or a business line of credit first. The effective cost of factoring (when you calculate the discount plus fees) was about 35 percent annualized for us. A business line of credit would have been 8-12 percent.