TurboTax Online is equipped to handle around 1,500 individual transactions (give or take) per brokerage account before the performance starts to deteriorate.
If you need to enter a bunch of stock transactions with a total sales volume of less than $10,000,000 (ten million), you can enter a summary for each sales category.
Another alternative is to switch to the TurboTax CD/Download software which handles around 2,000 individual transactions per brokerage.
How to enter a summary in lieu of individual transactions
Your brokerage statements should include a summary of your transactions, grouped by sales category, for example, "Box A short-term covered" or "Box D long-term covered." You'll enter the summary info instead of each individual transaction.
- Open or continue your return (if it's not already open) and search inside TurboTax for the phrase stock sales.
- Select the Jump to link in the search results.
- Answer Yes to both Did you sell stocks, mutual funds, bonds, or other investments? and Did or will you receive a 1099-B form or brokerage statement for these sales?
- If you land on Here are all your 1099-B sales, select Add sales from a different brokerage. Then answer Yes to Did or will you receive a 1099-B form or brokerage statement for these sales?
- When asked how you want to enter your 1099-B, select I'll type it in myself.
- Select or enter your brokerage on the next screen and continue.
- On the following screen (Tell us about...), answer the questions until you reach the next screen. Select the second option, Let's enter a summary instead, and select Continue.
- You'll now be able to enter the total proceeds (sales) and cost basis, along with the sales category. Refer to your 1099-B for the amounts and category. When finished, select Continue.
When you are done, you'll eventually come to the Here's a summary of your broker sales screen where you can edit, delete, or enter more sales.