The 25% rule is the concept that a local government's long-term debt should not exceed 25% of its annual budget. Any debt beyond this threshold is considered excessive and poses a potential risk, as the municipality may have trouble servicing the debt. The 25% rule also refers to a technique for determining royalties, which stipulates that a party selling a product or service based on another party's intellectual property must pay that party a royalty of 25% of the gross profit made from the sale, before taxes. The 25% rule also commonly applies to trademarks, copyrights, patents, and other forms of intellectual property.