Prescription is a term used to indicate that the time period to institute legal proceedings against a debtor has lapsed. It is thus not a legal term that should be easily ignored, as having your claim prescribe might mean the end of the road for any legal proceedings against a debtor.
When customers do not pay on time it seriously affects the cash flow of a business. Accordingly, when cash flow has been affected, it is difficult to rationalise paying a law firm to assist with the collection of the debt. This is a typical business Catch 22 situation.