The problem
Half a sale is the hardest kind of sale to keep track of.
Nothing in an optical shop completes on the day. Every open order is a frame you cannot sell to anyone else, a lab job you are waiting on, and a balance somebody still owes you.
Day 1A customer chooses a frame and pays half. The frame goes in a drawer with a slip of paper, and as far as the stock figure is concerned it is still for sale.
Day 2The lens order goes to the lab. Which lab, at what cost, against which customer — all of that lives in a WhatsApp thread.
Day 6Another customer wants the same frame. The system says there is one. There is not, because it is in the drawer.
Day 10The job comes back. The balance is collected, sometimes. Whether the deposit was ever recorded against this customer is a separate question.
Month endDeposits held, jobs outstanding and frames committed are three numbers nobody can produce, so none of them appear anywhere in the accounts.
What it actually costsMoney you already hold, against goods you have not yet handed over
Deposits are the part most retail software ignores, because most retail hands the goods over at the till. Here they are a running liability and a real part of your cash position.