We do run credit checks on occasion. I am not a lawyer, but I don't think there is any liability involved. That is one of the many things Dunn & Bradstreet does for a living. Is it worth it is a very different question. I have found it to be by and large a waste of time. Having a close and personable relationship with a customer is a great way to make an impression.
Our policy on collections on commercial customers is pretty straight forward (and State laws vary greatly). You get a bill, Net 30. A reminder at 60 if you still owe (that is less than 15 percent of our billing). After 90, we put someone in front of you. We become a squeaky wheel. In 28 years I have only had 2 installs that would not or did not pay. The first one was a small claims win and a waste of time. The second was much larger and convoluted, but we got most of our money; legal fees are still pending. So frankly, it is rare.
We don't use collection companies. We select our customers carefully (we can read reviews too) and our staff is tenacious. We also partial bill almost all jobs if the installation runs over 30 days. If you don't pay that partial, you are on credit hold and work stoppage until you do. It helps to get downpayment money from new customers. That weeds out a lot of problems.
Collection companies serve a purpose in this world, they just don't reflect the tenor or tone of our business.