How do I know if my state taxes are paid

[DoninGA]

Proof of payment is the cancelled check, bank or credit card statement showing the payment depending on how you chose to pay the taxes owed.

[xmasbaby0]

Hopefully you did not think your state tax was being paid by your federal refund---that is not possible.  You have to pay the state using the state's preferred method--usually that is by check or money order, or by using the state's tax web site to make an online payment.