What phrase must you hear from ATC to begin an approach?

To begin an approach, the critical phrase you must hear from Air Traffic Control (ATC) is "Cleared for the approach." This authorization is essential because it signifies that you have received clearance to commence your approach to the runway, indicating that ATC has assessed the current traffic and weather conditions and deems it safe for you to begin the landing sequence.

This phrase reassures pilots that they are following the prescribed procedures and regulations required for a safe and orderly landing, which is fundamental in air traffic management. Without this specific clearance, proceeding with the approach could lead to potential conflicts with other aircraft or violate operational protocols. Other phrases may suggest readiness or preparation for landing, but without the explicit clearance, the approach cannot officially begin.