No, you can't enter a negative line item. Sometimes, the advice and help are really bad.

So many helpful answers go as far as to explain the absolute obvious and stop before explaining the stupid result resulting from that shallow assistance. Such as sub-customer and parent customers, and addressing the invoices to the Job Name (i.e. sub-customer?). Who the hell decided that would be a great solution? I have many jobs with One contractor, and having my invoices addressed to a job Name and not their offices is so ridiculous. Why not just have a JOB NAME data input slot? What the hell? this sucks, workarounds in QBO after this many years of development and no job name entry. F$%%&&$##@CK! Should have Job Name: Job Address: Job Contact Name: Job Contact Phone Number: etc...

And the QBO official says we have 12 custom fields, dont they know their own products, we get 3, only 3 that will print on estimates and invocies..ONLY 3 NOT 12, AND THE 3 LEAVE SPACE FOR A 4TH ONE BELOW THE 3RD ONE TOTALLY WASTED SPACE. you guys need to wise up, and look at your products. F$%%&&$##@CK!