What is Tax Liability?
Your tax liability is the total tax you owe for the year, before counting what you've already paid in.
How it works
It's the figure the brackets and credits produce. You then subtract your withholding, estimated payments, and refundable credits. If those payments exceed your liability, you get a refund; if they fall short, you owe the difference.
A quick example
What people get wrong
A $0 refund with $0 owed is actually the ideal outcome — it means your withholding matched your liability exactly and you kept your money all year.