[Flyin'Dutch']

ATC is not the air police (and neither am I!) but if you have a transponder then the law now states you MUST use it.

Yep, I'm aware of that (and where it is fitted, I normally remember to turn mode S on!). The aircraft I'm referring to doesn't have one fitted though. Like I say, they'll probably refuse me at some point and I'll have to go over the top instead.

Sorry I misread your initial post! Apologies

[DarrenL]

Sorry I misread your initial post! Apologies

No worries. Misreads are a forté of my own. However, it's rather curious that the latest GEN 1.5 on the topic states with my bold:

5.3.1.1 - When flying outside of mandatory SSR airspace, all pilots are strongly encouraged to operate the transponder if equipped and to the full extent of its capabilities.

Which seems to be at odds with SERA.13001. I find all of this stuff increasingly difficult to follow. I guess I'm not alone!

[Dave W]

SERA is a Rule across EASAland; UK AIP GEN is not.

Follow the Rule.