To add to the above:
This is a company van, what is complicated?
That your only shot at this is the informal reps which I am sure will be rejected.
So:
Your employer gets the NTO
Their internal policies make incurring traffic penalties or charges a no-no. You've had many before, they're fed up and look at this as a way to dismiss you, perhaps; or
They don't know their procedural a**e from their elbow and send the NTO to you with instructions to 'get it sorted'. But you can't because you cannot submit reps in your name. So, do you draft and ask them to sign - 'I told you to get this sorted, not come back to me with excuses..' or sign pretending to be authorised and then find that a Notice of Rejection gets sent to the company who knew nothing about these reps..'
or..
The lease company gets the NTO, pays it and recharges your employer with admin costs, or
The lease company doesn't know their procedural a**e from their elbow and simply send the NTO to your company 'get this sorted'..etc etc.
When I said complicated, I meant complicated!
However, if managed properly you minimise the chances of the above.
You should find out who is the registered keeper and tell your employer that you have a PCN which you are challenging and that if it could go further you'll let them know in good time.