Populating as many fields as possible will narrow the search. Fields can be left blank if data is unknown.

The ICONN database is unable to reflect pooled blocks, but it does reflect the Host CLLI associated to an NXX. For a break-down of pooled NXXs see the NeuStar web site at http://www.nationalpooling.com. For a break-down of NXXs please see the NANPA web site at http://www.nanpa.com. The LERG database also reflects this information and should be used for routing purposes.