There may be too many transactions to download. It's OK to report 1099-B sales by category totals. In addition to long term and short term, they have to be broken down by sale category: Short term, Long Term and covered, noncovered, reported. not reported. You will also need to mail a copy of your 1099-B showing all of the transactions and totals to the IRS along with Form 8453:
Here are the mailing instructions:
If you are e-filing your tax return, then mail your statements along with Form 8453 to:
Internal Revenue Service
Attn: Shipping and Receiving, 0254
Receipt and Control Branch
Austin, TX 73344-0254
If you are not e-filing, then mail your statements with your entire tax return to your local IRS office.
If you choose to summarize, (or your broker is giving you a summary) you have to mail the transaction details to the IRS within three business days of IRS accepting your tax return.
Exception
: if you summarize Category A or Category D, Form 8949 is not needed for transactions without adjustments. No mailing is necessary.As an active investor, be aware that your category Box A sales without adjustments do not require Form 8949, so there is no reason to import those transactions.
instead use the "enter a summary" option to put your numbers on Schedule D Line 1a.
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If you have wash sales, it gets more complicated since those adjusted transactions have to be itemized on Form 8949 and the summary totals adjusted accordingly.
Enter the wash sales on Form 8949, then use the subtotal results on the bottom of that form to know how much to subtract. Be sure to NOT check the adjustments box in the summary window. TurboTax won't ask you about wash sales if you don't check the box.