When you buy $5,000 of stock, you did not lose $5,000. You swapped $5,000 of cash for $5,000 of goods. You are exactly as well off as you were a minute earlier — the value just changed shape.
The expense arrives later, when the items actually sell. That is Cost of Goods Sold.
What the entry looks like
Buying it:
| Account | Debit | Credit |
|---|---|---|
| Inventory (an asset) | $5,000 | |
| Bank | $5,000 |
Nothing touched the Income Statement. One asset became another.
Selling an item that cost you $20:
| Account | Debit | Credit |
|---|---|---|
| Cost of Goods Sold (an expense) | $20 | |
| Inventory | $20 |
Now it is an expense — matched to the sale that caused it, in the same period as the revenue.
Why anyone would care
Because treating the purchase as an immediate expense makes your reports lie twice.
Say you buy $5,000 of stock in January and sell it through March.
- Expensing it in January: January shows a $5,000 loss it did not really suffer. February and March look unusually profitable, because their sales carry no cost at all. Three months, all wrong, in both directions.
- Recording it properly: January is flat. Each month afterward shows its own sales against the cost of exactly the goods that sold. Every month is comparable to every other.
The second version is the only one you can make decisions from. The first punishes you for restocking and rewards you for running out.
The knock-on effect on cash
This is where sellers get caught, and it is worth stating plainly: a profitable month can still be a month your bank balance fell.
If you earned $3,000 of profit and bought $8,000 of stock, you are $5,000 down in cash and $3,000 up in equity. Both are true. The Income Statement shows the profit; the Balance Sheet shows where the money went.
Growing sellers hit this constantly — growth eats cash, because you buy the stock before you sell it. It is not a bookkeeping error, and reading only the profit number hides it completely.
What SalesImporter does with it
Item cost is tracked per item, so when a sale comes in from a marketplace, the cost of that item is posted to COGS at the same time as the revenue. The two land in the same period without anyone having to remember to match them.
What it cannot know is what you paid for stock you never told it about. Inventory costs have to get into the books somehow — through an item's cost, a bill, or a manual entry — or your Gross Profit will look far better than it is.