This looks like good advice. So I'll probably follow it.
https://ttlc.intuit.com/questions/1491785-can-i-import-sale-and-cost-basis-information-directly-from-an-excel-spreadsheet-into-the-turbotax-spreadsheet-or-directly-to-the-irs-form-8949You cannot go directly from Excel to Turbotax. You would need to convert the spreadsheet into a TXF file. A Google search on "Excel to TXF" might work, but some of the results are commercial programs not affiliated with Turbotax. An easier way would be to merely attach an Excel spreadsheet.
If you just list the totals from a worksheet or spreadsheet it must be the same as the column headings on Form 8949. If you do, you can still e-file. Within 3 days of filing acceptance of your e-file, you should complete Form 8453 (
http://www.irs.gov/pub/irs-pdf/f8453.pdf ). The Form is mailed with your securities list, in the format of Form 8949, and mailed to the the address listed in the instructions.
Instructions for Form 8453 include the following:
If you are filing your tax return using an online provider [such as Turbotax], mail Form 8453 to the IRS within 3 business days after you have received acknowledgment from your intermediate service provider and/or transmitter that the IRS has accepted your electronically filed tax return. If you do not receive an acknowledgment, you must contact your intermediate service provider and/or transmitter.
Is there a bitcoin tax website that automatically sorts out all my Mtgox transactions into easy to print Excel sheets?