A friend just phoned to tell us he is on his way out of the country early tomorrow morning.

He has been here on a single entry non O visa and working as a volunteer teacher with a work permit

First off he wants to know if his work permit has to be cancelled or does it just lapse when he leaves the job, country.

His employer says no problem just go but he is worried there could be a problem.

If it is still valid, it has to be cancelled. That might prevent troubles in the future.

it simply is filling a form and the school or he himself can send it.

WP cancellation form and instructions:

wp_cancellation.pdf

Thanks

I will get back to him.

Any problem with him leaving the country before it is cancelled?

No problem.