Section 22.919 in all of its technical detail was adopted in late 1994 and did not officially become effective until January of 1995. The FCC has had a policy prohibiting ESN modification, however, since the earliest incarnation of its cellular regulations. Below is the full text of an FCC Public Notice explaining the policy as it existed prior to adoption of Section 22.919.

It has come to the attention of the Mobile Services Division that individuals and companies may be altering the Electronic Serial Number (ESN) on cellular phones. Paragraph 2.3.2 in OST Bulletin No. 53 (Cellular System Mobile Station - Land Station Compatibility Specification, July, 1983) states that "[a]ttempts to change the serial number circuitry should render the mobile station inoperative." The 1981 edition of these compatibility specifications (which contains the same wording) was included as Appendix D in CC Docket 79-318 and is incorporated into Section 22.915 of the Commission's rules.

Phones with altered ESNs do not comply with the Commission's rules and any individual or company operating such phones or performing such alterations is in violation of Section 22.915 of the Commission's rules and could be subject to appropriate enforcement action.

Questions concerning this Public Notice should be addressed to Steve Markendorff at 202-653-5560 or Andrew Nachby at 202-632-6450.