Work doesn’t affect (PIP) in so far as PIP is not means-tested and you can be paid PIP whether you are working full-time, part-time or not at all. So, you could work as a merchant banker earning millions and still be eligible for PIP if you meet the relevant disability conditions.
However, you do need to be aware that work can affect the points you score in your PIP assessment and thus whether you are eligible for an award and at what rate. This is because any physical or mental activities that you undertake in the course of your work, or more probably any activities the health professional assumes you undertake, can be taken into account when deciding what points you score in the PIP medical assessment.
So, if your work involves moving around then this can be taken into account when deciding what you score for the mobility component of PIP. And if you manage to get yourself out of bed, washed and dressed, buy a bus or train ticket and travel to work then this can all be taken into account for both the daily living and the mobility components of PIP.
Any activities in your place of work, such as writing or typing, talking to customers or colleagues and moving around the workplace can also be taken into account.