The Wireless Telecommunications Bureau (WTB) audited the construction and operational status of various stations previously subject to rule based construction and operational requirements. This audit was undertaken to improve the accuracy and integrity of license data in the Universal Licensing System (ULS).

The PLMRS Audit included most Private Land Mobile stations (radio services IG, YG, PW, YW) operating on coordinated frequencies below 800 MHz.

The FCC mailed three audit letters to licensees, who were required to respond and indicate whether or not their stations included in the audit were 1) constructed and 2) operational in accordance with parameters of their most recent FCC authorization. The PLMRS audit is now completed and the final list of call signs that failed to provide a valid response is attached to Public Notice DA 04-1553 (pdf) released on June 8, 2004. The audit was successful because it had a response rate of 98% and cancelled 37,448 licenses out of 420,112 licenses audited.