Refer to figure.
Note: Under the latest Standardised European Rules of the Air (SERA), in the event of lost comms, there is a new squawk code:

• VFR = Squawk 7600
• IFR and continuing with your IFR flight – even if you’re in VMC = Squawk 7600
• IFR in VMC and you decide to land at the nearest suitable airport instead of continuing the flight = Squawk 7601 This new code informs ATC that you are diverting and so they can plan your separation.

In case of communication failure for a VFR flight in VMC:

1. Continue to fly in visual meteorological conditions (VMC).
2. Land at the nearest suitable aerodrome.
3. Report your arrival by the most expeditious means to the appropriate air traffic services unit.

ICAO Annex 2

3.6.5 Communications
3.6.5.2 Communication failure. If a communication failure precludes compliance with 3.6.5.1, the aircraft shall comply with the voice communication failure procedures of Annex 10, Volume II, and with such of the following procedures as are appropriate. The aircraft shall attempt to establish communications with the appropriate air traffic control unit using all other available means. In addition, the aircraft, when forming part of the aerodrome traffic at a controlled aerodrome, shall keep a watch for such instructions as may be issued by visual signals.

3.6.5.2.1 If in visual meteorological conditions, the aircraft shall:

a) continue to fly in visual meteorological conditions; land at the nearest suitable aerodrome; and report its arrival by the most expeditious means to the appropriate air traffic services unit;

b) if considered advisable, complete an IFR flight in accordance with 3.6.5.2.2.