Help with changing items after a deposit is taken.

[Texascannonfrio]

I take a 25% deposit upfront for wedding catering. The clients must give me final headcount within two weeks. Sometimes that is lower or higher than the initial invoice. Can I change the quantity or pricing and the customer pay the difference. Ex: 100 people x $25 = $2500 and a deposit of $625 remaining $1875. Final head count is 80 people x $25 = $2000 remaining balance now $1375 because client paid $650 for original quote. Does square automatically adjust the remaining balance after editing the invoice? Or require clients to pay the whole new amount? 

[alexandriak]

I've added items to invoices and it's just updated the balance due. I would imagine removing items would be the same