Invoice Auto Complete Items

Hello, how can I not allow non-existent items in invoice creation from being saved/processed? Thanks

That's not possible.

This might be a deal-breaker for many. I'm a freelancer that delivers services on a project-basis. In the invoicing software I use now every invoice item is unique (name of the project + a short description of what I've done). I don't want to create a new entry under "Items" just for one invoice.

Is there absolutely no way around this? :(