If you put in a zero for beginning & ending inventory figures it will expense all the "inventory" so just go with the flow. 

Hi:

I am unable to remove a choice to claim an inventory on small businesses (Sch. C) for my wife and myself.  I've decided to skip inventory on both.  Regardless of how many times I try to click NO on inventory it comes up YES.  How can I delete the YES permanently?  I never entered an amount for inventory for either business so it's not that.

I've tried this in both the Online and Desktop programs and don't have the same experience. If I first select that I have an inventory and then go back and say I don't, The change to "No" sticks. If I say I have an inventory but don't enter any numbers, nothing happens. I have no issues or error messages. If you are getting error messages about this, I'd recommend deleting the Schedule C's completely and starting them over. If you aren't getting errors, I'd just continue filing my return.