Compare inventory CSV files by SKU and warehouse
A SKU can appear in more than one warehouse. Match the location as well before reviewing quantities.
When comparing inventory CSV files, SKU alone may not identify a row. If the same product exists in several warehouses, use SKU and warehouse together. If your export separates batches, bins or variants, the key may need those identifiers too.
Work out what one stock row represents
In this synthetic example, SKU PEN-02 has 12 units in NORTH and 8 in SOUTH. A later export shows 10 in NORTH and 8 in SOUTH. Matching by SKU and warehouse identifies the change in NORTH without confusing it with the unchanged SOUTH record.
| SKU | Warehouse | Earlier units | Later units |
|---|---|---|---|
| PEN-02 | NORTH | 12 | 10 |
| PEN-02 | SOUTH | 8 | 8 |
Do not put quantity into the key. Quantity is the value whose change you want to detect. Adding it to identity turns a change from 12 to 10 into two unmatched records.
Check the meaning of quantity
On hand, available and reserved can describe different stock measures. Map equivalent definitions, not just similar headings. Also check whether units mean individual pieces, boxes or another pack size. A comparison does not infer those business rules or calculate a unit conversion for you.
Compare the exports
- Export the same warehouses and product scope from both sources.
- Load the files and map SKU, warehouse and the quantity fields.
- Select the identifiers as a composite key.
- Run the comparison and inspect duplicate-key warnings before accepting row pairings.
- Filter changed records, then review records present in only one export.
Explain missing rows before correcting stock
Some exports omit zero-stock items. Others include them. A missing product row therefore does not establish that the quantity is zero. Check the exporter’s filter and include-zero settings before making changes in the source system.
Export times matter too. A stock movement between snapshots can create a legitimate difference. Keep the timestamp and selected warehouses in your review notes. Spreadsheet Comparison reports differences; it does not determine which inventory system is authoritative or write corrections back.
For repeated SKUs, see the duplicate-key guide. For unmatched products, use the missing-row checklist before interpreting them as additions or removals.