On 1 May 2025 new amendments to SERA came into force, including a new transponder code for radio failure during IFR flight.
Under SERA.14083 (c)(6): if an IFR flight enters visual meteorological conditions and the pilot-in-command decides to continue in VMC, the pilot shall select Mode A code 7601, land at the nearest suitable aerodrome and report the arrival to the appropriate air traffic services unit as soon as possible.