Bulk import and export without breaking your data
Every warehouse starts with a spreadsheet: a catalog, a stock count, a list of open orders. NextStock imports them in stages, maps your columns, validates every row and shows a preview before anything is committed. If an import turns out wrong, you can revert it.
Highlights
Mapping templates
Map your column names once and reuse the template the next time the same file arrives.
Validate and preview
See every row that fails and why, and preview the result before committing.
Resumable commits
Large files commit in chunks, so an interruption resumes where it stopped instead of starting over.
Revert an import
Undo a committed import when the source file was wrong.
Why bulk imports go wrong
A bad import is one of the fastest ways to lose trust in a new system. A column shifts by one, a unit of measure is read as cases instead of eaches, or half of a large file loads before the upload times out. Now you have partial data and no clean way back.
The usual workaround is to import in small batches and check each by hand. That is slow, and it still misses errors that only show up when two rows conflict. A staged import catches those problems before they reach live stock.
How a staged import works in NextStock
Each import runs through the same steps, whatever the data.
- Upload a CSV file and choose what it contains.
- Map your columns to NextStock fields, or apply a saved mapping template.
- Validation checks every row: missing fields, unknown SKUs or locations, duplicate codes, bad dates.
- Preview what will be created or changed, and fix the file if needed.
- Commit. Large files commit in chunks and can resume after an interruption.
- Revert a catalog import, or reverse a stock import with a correction import, if you later find the source was wrong.
What you can import and export
Bulk import covers the data most warehouses start with or receive in batches.
- Catalog: products, variants, pack sizes and barcodes. Product images can be bulk imported by URL or ZIP.
- Opening stock: quantities by location, with lot and expiry where tracked.
- Sales orders, for channels without a live integration.
- ASNs and purchase orders from suppliers.
- Pick faces with their min/max levels.
Opening stock goes through the ledger
Opening stock is not typed into a balance field. Each imported quantity is posted as a movement on the inventory ledger, with a reason and a reference to the import. Balances always equal the sum of those movements, so the starting position is auditable from day one.
That is also how a mistake is undone. A correction import posts the opposite movements, rather than editing numbers by hand, so the history shows both the load and the fix.
Exports, count sheets and CSV downloads
Data goes the other way too. Bulk export gets records back out as CSV, which makes round trips practical: export the catalog, correct pack sizes in a spreadsheet, and import the changes. Count sheets support sites that still count on paper or in a spreadsheet, with lists that follow the walk sequence of the floor. Bounded CSV downloads from lists cover quick analysis without pulling the whole database.
Tips for a clean first import
Import in dependency order: warehouses and locations, then catalog, then opening stock, then open orders. Run the catalog first on a small file to prove your mapping, then load the full file. Count before you import opening stock, not a week earlier, or you will be adjusting from day one.
The spreadsheet to WMS migration guide covers the cutover plan in detail. For integrations that need live data rather than files, see API and webhooks.
Built for
Frequently asked questions
Short, direct answers to the questions warehouse teams ask most.
What file format does NextStock import?
CSV files. You upload the file, map its columns to NextStock fields, and save the mapping as a template so the next file from the same source imports without remapping. Product images are the exception: they can be imported in bulk from URLs listed in the file, or from a ZIP archive of image files.
What happens to rows that fail validation?
Nothing is committed until you have seen the validation results and the preview. Failed rows are listed with the reason, such as an unknown SKU, a missing location or a duplicate barcode. Fix the source file and upload again, then commit once the preview shows what you expect. This keeps partial or inconsistent data out of live stock.
Can I undo an import?
Yes. A committed catalog import can be reverted. Opening stock works differently: because it posted ledger movements, you undo it with a correction import that posts the opposite movements, so the history stays complete and balances stay consistent with the ledger. Revert is meant for a file that turned out to be wrong; for small corrections after work has started, an adjustment with a reason is usually cleaner.
How large a file can I import?
Large files are committed in chunks, and a commit that is interrupted can resume from where it stopped instead of starting over. For very large catalogs, split the file by product range so validation results stay easy to review. Test with a small file first to confirm your column mapping.
A little more order. A lot more possibility.
Make space for a better way to run your warehouse.