The regulation for a PPL is "not for hire or reward". While you've got the personal reward part mostly eliminated, there is still an implication here that you are operating for hire. It could also be interpreted that the company you're working for will collect some reward for offering the service, and you might also need the company to not pay your salary for those hours that are being flown.
Also think about insurance. - who will cover the costs in the case of an accident?
I would definitely get approval from the authority before doing this. And get it in writing.