I'm finalizing my taxes and noticed that on the Form 8949 under "Description of Property" column, it says "See attached statement". I don't have a statement to attach. When putting in the information that goes on this form, I opted for the "summary" data because the information provided by Coinbase did not include specific purchase/sale dates but used "various". What, exactly, am I supposed to attach here, how do I attach it if I'm e-filing, and what happens if it's not attached?
TurboTax should have generated Form 8453 when you selected that you want to enter a "summary" of your Coinbase transactions.
You aren't able to attach the Coinbase detail information when you E-file however, per the instructions for Form 8453, you have three days to mail in your Coinbase information as support for your "summary" along with Form 8453, after the IRS has accepted your return. There's no cover letter.
Mail Form 8453, with your attachments to:
Internal Revenue Service
Attn: Shipping and Receiving, 0254
Receipt and Control Branch
Austin, TX 73344-0254
Related information: