Seriously, it’s a rabbit hole. You can get discounts on phone contracts (O2’s “Feel at Home” for disabled customers), cheaper internet from some providers, and even reduced gym memberships if your PIP relates to a condition.
Some energy companies offer a Priority Services Register for PIP claimants—they’ll send you advance warnings of power cuts, or even help you read your meter if you can’t.
Oh, and don’t forget the free NHS prescriptions if you’re on PIP and also get Income Support or UC. Because why pay for paracetamol when you could buy a coffee instead?