All amateurs must be registered with the FCC. This is not an option.
If you are not registered when seeking FCC services, the application will be returned without action. You are not required to register until the first time you intend to file an application, however. For most Amateur Radio operators, this will be when you renew or modify your license (that is, change your address, name or call sign, upgrade your class of operator license, or apply for a vanity call sign).
Amateur licensees registered in ULS already have been cross-registered in CORES and issued an FRN by mail. Amateurs can check to see if they have a Federal Registration Number (FRN) electronically via a ULS License Search. Many Internet call sign servers, including ARRL's, also can provide this information.
All amateurs who register in CORES will be issued an FRN. Amateurs then should use their FRN in place of their Taxpayer Identification Number (TIN--typically an individual's Social Security Number) when filing applications with the FCC. New or upgrade license applicants not previously registered in ULS will be registered automatically in both CORES and ULS when they provide a TIN on a license application filed through a Volunteer Examiner Coordinator or on a form submitted directly to the FCC. An easy ways to determine if you have already registered, or if you have been auto-registered is to check the CORES and ULS databases. Your FRN should appear in both.
Although both ULS and CORES will contain a licensee's FRN, updating information in one system will not update the other. For amateurs, CORES registration replaces ULS ''TIN/Call Sign'' registration, but the ULS will remain the Amateur Service licensing database, and only ULS will associate an individual with a particular call sign and FRN. Now that CORES and FRN's are mandatory, those registering in ULS will be redirected to CORES registration when filing electronically.
The FCC has discontinued issuing an Assigned Taxpayer Identification Number, ATIN's, which the FCC had been issuing to applicants ineligible to obtain a Social Security Number, such as foreign applicants and club station licensees. Applicants who had been using ATINs must now register in CORES. CORES will offer exemptions to amateur clubs and to foreign entities not holding a TIN/SSN.
All passwords will be maintained in the CORES database. Amateurs also may use FCC Form 160 to register manually in CORES, and those doing so will be mailed a CORES password for on-line access. Once the FRN is obtained, amateurs registering manually must complete an FCC Form 606 to associate a call with the FRN.