Last year, I received a letter saying that I owed $600 to the state of Indiana. By mistake, I paid $600 on the IRS website. Is there a way i can get that money back?

[ThomasM125]

Yes. The money you paid to the IRS will be applied to the year you entered. If that is before the current tax year, 2024 in this instance, you may have the money applied to your tax when you file your 2024 tax return and it will be refunded to you without you doing anything further. Otherwise, you would eventually get a notice of an overpayment which would give you an option to have it refunded. You can also call the IRS at 1-800-829-1040 and they may be able to expedite the refund of it.

[fanfare]

amend your tax return that did not show the entire amount of "tax you paid".  See 1040-X Line 16.

you  must act within three years of the tax return due date