Originally Posted by
kaposznyak
So flying VFR, in uncontrolled airspace (Class F) with a Z-type flight plan (first VFR, later at a given point IFR) what is the standard phraseology for changing to IFR?!
In uncontrolled airspace in the UK, none. In the UK there is no requirement to communicate with anybody whilst flying within unregulated uncontrolled airspace. Simply change from VFR to IFR as and when required.
If you require a Surveillance Service freecall a Lower Airspace Radar Service unit and request Traffic Service or Deconfliction Service.