Why is trade discount not recorded in books of accounts?

Product catalogs often provide a list price for an item. Those list prices may bear little relation to the actual selling price. A merchant may offer customers a trade discount that involves a reduction from list price. Ultimately, the purchaser is responsible for the invoice price, that is, the list price less the applicable trade discount. Trade discounts are not entered in the accounting records. They are not considered to be a part of the sale because the exchange agreement was based on the reduced price.