I made a donation of stock to a charitable organization. In identifying the tax lots from my total position in the stock I made a mistake and allocated the donation to the highest cost rather than the lowest. When I contacted my brokerage firm they claimed that the IRS rules do not allow for any changes in tax lot allocation after the settlement date. I have searched the IRS site and have been unable to find anything about making changes. I have spoken to another brokerage firm and they told me that changes are possible on a one off basis. I assume this is not an uncommon mistake and there should be some allowance to correct an innocent ( STUPID!) mistake?
Any help would be appreciated
Thanks in advance