The standard ICAO clearance delivery procedures usually require flight crewmembers to pick-up their clearance on the taxi out as opposed to the U.S. method of receiving clearances from a discrete clearance delivery frequency prior to starting engines.

The result of this procedure is often a very rushed feeling during taxi if you are not accustomed to the procedure. Picking up a clearance during taxi, coupled with language barriers and unfamiliar terminology, can lead to lead operational errors where aircraft are not configured correctly for takeoff or FMS routes are incorrectly entered.

It is standard operating procedure to carefully review the filed flight plan and departure procedures which pertain to the intended direction of departure. Then, when a clearance is received on the taxi, it will be much easier to recognize fixes and procedures. It is also essential to brief the anticipated taxi route prior to taxi in order to avoid task saturation from trying to navigate the airport while requesting a clearance and performing checklist items. Flight Plans shall also be resubmitted when departing later than 30 minutes from the planned departure off block time per ICAO Doc 4444.4.5.5. Flight crewmembers shall also be mindful that the clearance received may not be a full route clearance as in the United States. Often times a clearance will be received to an intermediate fix, usually at the border to foreign airspace.