North American component Marks

UL's North America component certification program includes two marks, the traditional UL in a Circle Mark and the backwards "UR" Mark.

Listing Mark

The UL Listing Mark is the traditional Mark of UL and the most well know UL Mark. This mark is intended for end-products and complete components. Components covered under UL's Listing Service are suitable for factory and field installation.

All components which bear the UL Mark are under UL's Follow-Up Service (FUS) program. UL's rigorous FUS Program verifies that the components which bear the UL Mark continue to be manufactured in compliance with UL's safety requirements.

Recognition Mark

UL's second component mark is the Component Recognition Mark. The mark consists of a mirror image of "UR" - meaning UL Recognition. Components covered under this program are considered incomplete and are intended to be installed into another device, system or end-product. Components covered under UL's Recognition Service are only intended for factory installation, not field installation.

When a complete product or system containing Recognized components is evaluated, the evaluation process is streamlined for the benefit of end-product customers. Components may have restricted performance capabilities that limit their application. 

UL's evaluation may include a constructional examination and testing of the component. Guidelines addressing the suitability of the component when used in the end product application are included in the UL Report as "conditions of acceptability." The ratings and conditions of acceptability for some components are additionally included in UL's Component On-line Databases. Learn more.

All components which bear the UL Recognized Marking are under UL's Follow-Up Service (FUS) program.  UL's FUS Program verifies that these components which bear the UL Recognized Marking continue to be manufactured in compliance with UL's safety requirements.

Find additional information regarding the difference between the UL Listing and UL Recognition Marks.

For a complete listing of the UL Marks available, visit our about UL Marks page.