I filed my Grandmothers taxes in 2006 through her accountant. She sold some stock, and ended up owing $1100, which was paid. I have received a letter from the IRS stating they have not received her 2006 tax statement, and she has an $1100 credit which she will lose after this April. Her accountant has not returned my calls to question this. The IRS says she needs to resubmit a copy of newly signed tax return. She passed away last month, since this has already been paid, will not acting affect her estate in anyway? Can I submit a copy of her previously signed 06 taxes?