What is the proper ICAO phraseology to activate a flight plan? OK, so you have a flight plan filed (over internet, phone, company or however), go to the aircraft and get in the cockpit. So you call the controller and request IFR or VFR as appropriate.


What is the recommended wording of the request and how it is actually pronounced? Is “IFR” spelled, like “requesting eye-eff-are”, using phonetic alphabet like “requesting India Foxtrot Romeo” or expanded like “requesting instrument flight rules”?
Should you add the destination or other description of the plan? The ATC already has it, but it might serve as a check.
Do you call only when you are almost ready for start up or push back, or earlier in the preflight? And if earlier, do you also add some indication when you will be ready?


I'm asking about both VFR and IFR flight plans.
The UK CAA Radiotelephony Manual (CAP 413, Edition 22, May 2016) has an example of how to activate a flight plan in chapter 3, section 3.36 (page 92 in the PDF).


  Aircraft G-CD, departed Seton at 38 request activate flight plan
  ATC G-CD, departure time 38 will activate flight plan


There is no indication whether this is for VFR or IFR flight plans, so it should apply to both if a filed flight plan wasn't activated at departure.

I also pulled out my (fairly recent) radiotelephony textbook, which covers EASA up to and including PPL including in English (and thus should be pretty close to the official ICAO phraseology), to double-check what it says. (I don't often fly with an actual flight plan active.)


  Aircraft ATC callsign, aircraft callsign
  ATC aircraft callsign, ATC callsign, go ahead*
  Aircraft aircraft callsign, activating VFR flight plan, departed airport, hour hour minute minute, to destination airport
  ATC aircraft callsign, activating VFR flight plan, hour hour minute minute
  Aircraft aircraft callsign


For example, Smallprop 123 flying VFR in airspace controlled by Somewhere Control, with a previously filed but not yet activated flight plan:


  Aircraft Somewhere Control, Smallprop 123
  ATC Smallprop 123, Somewhere Control, go ahead*
  Aircraft Smallprop 123, activating VFR flight plan, departed Hometown, one two tree five, to destination Springfield
  ATC Smallprop 123, activating VFR flight plan, one two tree five
  Aircraft Smallprop 123


*) the "go ahead" may be omitted

The exception to this is if you are departing from a controlled airport, in which case a flight plan filed prior to departure is activated automatically. Activating a flight plan manually is only required when departing from uncontrolled airports.

To close a flight plan, the phraseology after establishing contact with ATC is:


  Aircraft Smallprop 123 position Wintermeadow closing VFR flight plan from Hometown to Springfield
  ATC Smallprop 123, flight plan closed at time one tree tree zero
  Aircraft Flight plan closed at time one tree tree zero, Smallprop 123