2015 Tax Bill and Statute of Limitations

Hello everyone,

I have just received a notice in the mail that I owe around $6,000 in back taxes from 2015. This is not from the IRS, but from another state that I lived in at the time.

This bill is mostly interest and fees, with only around $700 in unpaid taxes. I did file my taxes that year, and after doing some research, they are correct that I made a mistake and owe the $700.

I am frustrated because I didn’t receive any notice until now, and the interest and fines have been accumulating without my knowledge.

Are they allowed to pursue this bill 9 years later? I saw online that the IRS generally doesn’t go this far back. I will pay if there’s no other option, but it seems a little unreasonable. I would appreciate any guidance.

Which state?