Carriers that are not within the top 100 MSAs, and therefore are considered non-LNP-capable carriers, will not have to participate in number pooling. However, the Commission has directed these non-LNP-capable carriers to participate in creating the thousands-block pooling architecture so as to be ready to implement pooling as soon as they become LNP-capable, and, in the meantime, to further explore non-LNP alternatives to number conversation. Along these lines, as an alternative approach to number optimization, non-LNP-capable carriers will be subject to utilization thresholds to obtain growth codes. When a non-LNP-capable carrier becomes LNP-capable, whether voluntarily or pursuant to the Commission’s rules, that carrier will be required to participate in thousands-block number pooling in all pooling areas.

Thousand-block Number Pooling requires telecommunication carriers to modify significantly the manner in which they account for their inventory of telephone numbers.  This modification includes changing their Operational Support Systems (OSSs) and retraining their staff.  The FCC mandates the accounting for and reporting of all numbering resources in six primary categories. The carrier must maintain these records and report on them semi-annually as well as maintaining records for an additional eight sub-categories, which may be requested in the event of an audit.  The contracted Pooling Administrator will track numbering resources and manage the donation and assignment of numbering blocks within the pool based on the information obtained within these records.

Wireless carriers are also faced with the need to manage two separate numbering databases forced onto them by LNP.  The Mobile Directory Number (MDN), which is the dialable number,  will be issued in blocks of 1000 due to number pooling.  Mobile Identification Numbers (MINs), the non-dialable number that serves as the mobile identifier, will still be issued in blocks of ten thousand by a separate entity (MBI Administrator-not yet determined).  There also is a need to maintain yet another database of MDNs that have ported out of the wireless carriers network (no longer can be used but still have to be tracked in case the subscriber that "owns" the number eventually terminates service, at which point the MDN will snap back to the original wireless provider that initially owned it.)