I would need this feature as well. I have been tracking updates for a tip feature for QB invoices. It has been well over a year. I currently use Square for a lot of my sales but prefer to use Quickbooks because of the syncing feature. Is there a timeline in place for this tipping feature to be added and will we get an update when changes are made? The workaround you suggest is not feasible for my business as asking for tips upfront is not good customer service, in my opinion.