Hi.
Checking the EASA website, I came up with this.
It would depend if you are PiC or co-pilot. In the text it also specifies that PiC is appointed by the operator for the flight.
2. Logging of time
2.1. Pilot*in*command flight time
a. The holder of a licence may log as pilot*in*command time all of the flight time during which he is the pilot*in*command.
2.2. Co*pilot flight time. The holder of a pilot licence occupying a pilot seat as co*pilot may log all flight time as co*pilot flight time on an aircraft on which more than one pilot is required under the type certification of the aircraft, or the regulations under which the flight is conducted.
2.3. Cruise relief co*pilot flight time. A cruise relief co*pilot pilot may log all flight time as co*pilot when occupying a pilot’s seat.
http://easa.europa.eu/rulemaking/doc...202008-17b.pdf
Hope this helps
Edit: scroll down to page 173