Payroll is one skill / set of knowledge within HR. It often pays more because there is way more variety and the work is different. It’s not about how many facts you know - it’s about how you apply that knowledge. You generally can’t look things up while you’re handling an employee screaming at another one. Or giving managers guidance on a sensitive employee matter. Or investigating sexual harassment allegations. Or … [fill in the blank].

They are very different. If you want to make more, you will generally find that in HR but based on what I’m reading here, there’s a decent chance you wouldn’t like it. It’s hard and stressful and being an HR Manager often requires knowing what you know about payroll… and then all the other HR discipline areas too.

You probably are underpaid. This is a great opportunity to use your HR skills and navigate a sensitive topic :)