Every business that carries stock has the same conversation eventually. The screen says forty. Somebody walks to the shelf and counts thirty-six. Nobody is stealing anything. The four went out in ways that were perfectly ordinary and were never written down.
Stock does not drift. It leaks in specific places
It is worth naming them, because "our stock is always wrong" is not a problem you can fix and a list of five leaks is.
- A sale that did not go through a bill — the customer took it, you were busy, the invoice came later or never.
- Goods that went out on approval or for a job and have not come back, counted as gone when they are not.
- A purchase that arrived and was put on the shelf before the bill was entered.
- Breakage, expiry and samples — real reductions that nobody records because there is no document to attach them to.
- The opening figure itself, typed in once at the start and never verified against anything.
Automatic deduction fixes exactly one of those
When stock comes off the item as soon as you raise the bill, the first leak closes — and only that one. This is worth being precise about, because software is often sold as if it solved the whole problem. It does not. Everything that leaves without a document still leaves without a document.
In BizGST Pro the deduction happens in the database itself, on a trigger, rather than in the screen you happened to be looking at. The practical difference is that it cannot be skipped by billing from a different page or by a browser tab that closed at the wrong moment.
Not everything should be tracked
There is a flag per item for this, and it matters more than it sounds. A trader who sells packaged goods wants every item tracked. A service business with three consumables on the list does not, and turning tracking on for things nobody counts produces a stock report full of meaningless negative numbers — which is how people stop trusting the report at all.
The habit that actually closes the gap
Count. Not the whole godown, and not once a year in March when it is also everything else's deadline. Take the twenty items that move fastest, count those, and put the real number in.
The screen for it puts the system quantity and an empty box side by side, item by item. You walk the shelf, punch in what is actually there, and look at the differences before anything is saved. Most rows match; the ones that do not are the interesting part.
An adjustment is a record, not an eraser
This is the difference between a stock system you can reason about and one you cannot. When you correct forty to thirty-six, the correction is stored as its own movement with a note, alongside the sales and the purchases — not as a quiet overwrite of the number. Three months later the question "when did this item last get adjusted, and by how much" has an answer.
The same is true of transfers between locations and of stock taken in against a purchase. Each one is a line in the movement history with its reason attached. The current figure is the sum of those lines, which means it can always be explained.
What to look at once it is working
Two things. The low-stock list, which is only useful if the figures behind it are true — and they are only true once you have counted at least once. And the items whose adjustments are consistently in one direction, because an item that is always short by a little is usually a process, not an accident.
The honest summary
No software makes your stock figure correct. What it can do is remove the leak you can automate, record every deliberate correction so the history survives, and make counting cheap enough that you actually do it. The rest is walking to the shelf.