Which altitude change should a pilot report according to IFR practices?

According to IFR practices, pilots are required to report when they leave a cleared altitude to climb or descend to a new assigned altitude. This ensures that Air Traffic Control (ATC) remains aware of the pilot's altitude changes and can manage the traffic within their airspace effectively. Reporting such changes is crucial for maintaining safe vertical separation between aircraft and helps prevent potential conflicts during flight.

While there are specific altitudes and situations where reporting is essential (such as any altitude below 1,000 feet or climbing above 10,000 feet), the most pertinent requirement within IFR operations is the necessity to inform ATC when transitioning between assigned altitudes. It facilitates communication and enhances safety in busy airspace. Additionally, reporting any altitude achieved above cruising altitude is not a standard practice, as the primary focus remains on adhering to assigned altitudes and maintaining clear communication with ATC regarding altitude changes.