On the Number Search and Reserve (NUS) page, you can enter a Toll-Free Number (TFN) that has a “closed NPA or NXX” code and then select the “Search” button. Once the search results have been displayed, you can view the status as "Closed" with a message, “Specific NPA-NXX is closed” in the Results portion of the page.
Disclaimer: Any images in this article are intended to be used as a guide for educational purposes only and they may differ slightly from the Production Environment.