PIP, just like DLA, WPMS and every other kind of benefit is paid for out of the public purse.
That purse is filled by, and owned by, the taxpayer.
Ergo, every single penny paid out to individuals, corporations, companies, charities, the EU, etc, etc is by definition, tax payers money.
We are all taxpayers. Indeed I dread to think how much tax I’ve paid over the years but I am grateful for every penny I’m getting back. Sadly, too many people are only interested in how much they can sponge out of the public purse whilst being only too willing to moan about the austerity that they are partially fuelling.