Sales Report with negative amount

This can be caused by a corrupted file, DiogoIannaccone. I'll help you fix it.

Let's run the Verify/Rebuild utility to detect the data damage. Here's how:

1. Click File.
2. Go to Utilities, then choose Verify Data.
3. If QuickBooks detected no problems, there's no further action needed. If you receive a message, "Your data has lost integrity", the file is damaged. Just continue to Rebuild Data to correct the problem.
4. When you Rebuild Data, you'll receive a message to back up your company file, just click OK. The utility starts as soon as the back up is finished.
5. Click OK when you get the message "Rebuild has completed".
6. Run Verify Data again to check for remaining data damage.

Once done, pull up the sales report again and check the figures. 

You can also check this reference on how to fix data damage on your QuickBooks Desktop company file for more information. 

Feel free to reach out to us again after trying the recommended steps. We're just around to help you.

Chances are you sales items are set up incorrectly.  Please check your items and see if they are pointing to an expense account instead of an income account.  If you buy and sell items, you need to check off the box on item set-up screen that reads "this item is used in assembles or performed by a subcontractor or partner".  This will split your item screen and allow you to choose one account for purchases and another account for sales.  

I see this all the time when a customer invoices for an item set to an expense account.