Inventory accounting answers two questions: how much stock you have and where it is right now. On marketplaces it breaks more often than in retail: the same goods are simultaneously in transit, in the platform's warehouse, in a sorting center and in returns. Here is how to keep the books so that your stock figures actually match.
Why accounting is harder on a marketplace than in retail
The same batch can be split across several states: in transit to the warehouse, received, reserved for an order, on its way to the customer, coming back, sitting in your own warehouse under FBS. If your accounting only sees the stock figure in the seller account, you do not know real availability and you reorder blind.
Add a second or third platform and the picture falls apart without a single spreadsheet or service: turnover and dead stock, ABC analysis of the assortment.
What to track: the minimum set
- Batches and cost price. Every purchase at its own price: without it you cannot calculate profit — product cost price.
- Stock by storage location. Platform warehouse, your own warehouse, goods in transit, returns.
- Movements. Inbound shipment, sale, return, write-off, mis-sorting — each with its own date.
- SKU mapping. Your internal article number to the platform card: article number, SKU and barcode.
- Documents. Receiving records, delivery notes, discrepancy reports — the basis for both claims and accounting.
How to run it: spreadsheet, service or 1C
- Spreadsheet. A working option at the start and up to a few dozen SKUs: cheap and flexible, but it demands discipline and breaks easily as you grow.
- An inventory service for marketplaces. Pulls sales and stock over API, calculates cost price and profit. What matters is support for your platforms, accuracy in reconciling returns, and an export your accountant can use.
- 1C (Russian accounting software) and ERP systems. Justified when you have your own production, wholesale, or several sales channels besides marketplaces.
Whatever you choose, the source of truth for money is the platform report, not a service export: the Weekly Sales Report under Balance → Financial reports (how to read it) and regular reconciliation with the marketplace.
Stock counts and discrepancies
Discrepancies are inevitable: a receiving count that does not match, depersonalized goods, a return that never made it back into stock. A regular stock reconciliation — at least monthly — catches them while they are still a claim rather than a write-off: shortages and warehouse losses, short shipments and mis-sorting, returning stock from a WB warehouse.
Related reads: How to work with FBS.
FAQ
"How do I keep inventory records on a marketplace?" Record batches with their cost price, stock by storage location (platform warehouse, your own warehouse, in transit, returns) and every movement of goods, then reconcile all of it against the sales report each period.
"Do I need 1C for marketplace accounting?" Not necessarily. Up to a few dozen SKUs a spreadsheet is enough; beyond that sellers usually move to an inventory service with API integration. 1C makes sense with production, wholesale or several sales channels.
"How does inventory accounting differ from financial accounting?" Financial accounting answers to the tax office and works with documents and reporting periods. Inventory accounting answers operational questions: what to order and when, where the goods are, and what each batch cost.
"How do I calculate cost price if batches were bought at different prices?" Keep records by batch and write them off in a chosen order — usually FIFO. An average price across the whole warehouse distorts the profit on specific sales.
"Why does the stock figure in my seller account not match mine?" Most often because of goods in transit, depersonalization during receiving, returns that never came back, and write-offs. Every discrepancy is resolved through the receiving documents and the report, not by eye.
