How do I deduct a business loss?

[brethutson]

I invested approximately $150,000 in a small startup company in 2018 and within a few months it completely failed.  I would like to show this as a loss for income taxes.  The problem is that I have very little documentation.

[HelenaC]

You must keep records, such as receipts, canceled checks, and other documents that support an item of income, a deduction, or a credit appearing on a return. 

To enter your investment loss:

Open (continue) your return in TurboTax.

In the search box, search for investment sales then select the Jump to link in the search results.

Answer Yes to the question Did you sell any investments?

• If you land on the Here's the investment sales we have so far screen, select Add More Sales.

Answer No to the 1099-B question.

On the next screen, select the type of sale you had (like second home, collectible, or land) and Continue.

Continue following the onscreen instructions to enter the sale.