Applying for another position in company - what's the etiquette?

[woowooeoo]

I work for a county council which employs thousands of people across departments.

I'm wondering what the etiquette is in this situation if you want to apply for another role within the company, in a different directorate.

Do you tell your line manager you are doing this? Do you need permission to do this? Or do you just do it?

Surely it's awkward if you don't get the role and you still have to work with everyone who knows?

You can just do it. In a different directorate word might not get out. Or your line manager or other colleagues might well be on the panel. If you get on well with your manager let them know they may support you.