On 1 December 2022, the Lord Chief Justice of England and Wales, and Senior President of Tribunals, announced that with immediate effect all Employment Tribunal Judges and Employment Appeal Tribunal Judges are not to be addressed as ‘Sir/Madam’, but rather as ‘Judge’.
The reason for this change, apparently, is to reflect this important judicial role, while maintaining the necessary degree of respect.
If you are attending a tribunal as a witness, the non-legal members should still be addressed as Sir/Madam.