Is it legal for a contract to say that you can't also work elsewhere?

[AhTheFuckening]

Is this something that companies would be able to defend?

I'd consider it - either something related but not overlapping like something to do with AI in my speciality, or something completely unrelated like housesitting.

i doubt I would be allowed as my employer would want ‘first dibs’ on my time for urgent work out of hours. Generally should be available unless on holiday (I can take the time back), I doubt I’d be able to permanently block out long periods of time where I would be unavailable to them.

We have to seek permission to take on additional work. Not just potentially conflict of interest, but to ensure sufficient R& R. If you started another role, your focus could be dissipated and your health may be compromised, so risking your attendance and productivity in your main role.

Even if a contract says no, they can still agree to it if they are happy.
So if you seriously want to and think there won't be any conflict with your existing role then just ask if they would be happy for you to seek additional work

Thanks everyone 🙂.

If you get permission and it’s only part time you’d be ok, by polygamous working is becoming a thing and I’ve heard of a few cases lately where people have been found out and dismissed from both jobs. Couple of hours a week then sure , more than that, dodgy ground.