A Comp Check (also known as a "look-up") is a request made to a State Licensed or Certified real estate appraiser, sometimes to assure a minimum opinion of value before an order (typically for lending purposes), is placed. Because providing an opinion of value is the definition of an appraisal in the United States, the practice of the look-up, when excess care is not taken, runs a greater risk of being in violation of the Uniform Standards of Professional Appraisal Practice (USPAP) than an assignment with a more thorough Scope of Work.