An IA is valid only if the inspector has a fixed base of operation. The FAA requires a stable, identifiable place where inspections can be performed, records can be kept, and the authorizing authority can be reached. When the holder no longer has a fixed base of operation, that essential condition is lost, so the Inspection Authorization can no longer be considered effective. Renewal activity within a 90-day window relates to maintaining the credential, but it doesn’t by itself eliminate the authority immediately. Violating an FAR would lead to enforcement actions, not an automatic loss of effectiveness without FAA action. Changing employers can complicate the authorization, but the IA can remain valid if the new arrangement still satisfies the base-of-operation requirement and appropriate updates are made.