I track all of my income through quick books. When a customer sends a 1099-NEC for income thats already counted, do i still enter the 1099? income is counted twice then.

I track all of my income through quick books (Painting contractor). Every contract paid gets counted accurately along with expenses etc. Some of my larger accounts send 1099-NEC. My question is, do i still enter the 1099-NEC or leave it off so the income doesn't get counted twice making my taxes go up?