Maintaining accurate serial numbers is crucial for inventory management across many industries. With Assisted import, it's easy to add and update them.

Notes about importing:

Updates can only be done on items that already exist (unknown SKUs are skipped, and if no match is found, the import will encounter an error).
One location per import.

Note: Requires the Traceability add-on as well as the manage items and manage stock permissions.

Step-by-step guide

1. Open Assisted import

Navigate to Settings and find Data import from the left-side menu (under Import and more).

2. Upload your spreadsheet

Choose Serial numbers.
Drag and drop the spreadsheet into the box, or click Upload file.

Note: If the uploaded spreadsheet contains multiple sheets, only the first one will be included.

3. Column mapping

Each column in your file will be evaluated, and the AI will suggest mapping based on column names and data patterns.
1. Each field mapped by the AI will also be tagged with a qualifier (High, Medium, Low) indicating the AI's confidence in its accuracy.
Examine the mapping to verify that everything is correct. If fields are missing, drag-and-drop them from the unmapped column.
Note: Required fields must be mapped before import can proceed.
Once ready, click Proceed at the bottom of the screen.

4. Locations

Every location name in the file is listed with how many rows use it. Names that match a Katana location are marked Matched. For a name Katana doesn't know, or for rows with no location, pick a location from the dropdown or choose No location — skip these rows. A single row's location can also be changed in that row's Location cell further down.

5. Serial number stock options

Items without serial number tracking. If some items in the file don't track serial numbers, their rows are skipped, and Katana offers to turn on serial number tracking.

6. Data validation

This step validates each row in the file, ensuring it meets Katana’s rules (required fields, data types, value constraints, and uniqueness).
Rows are grouped into tables:
- ADDED: serial numbers that go into stock.
- EXPIRY UPDATED: serial numbers already in stock whose expiry date changes, shown as old → new.
- NO CHANGES: Already up to date — nothing to import.
- SKIPPED: rows that won't be imported, grouped by reason with Download Report.
- Invalid rows: format problems such as a blank serial number. Cells can be fixed by double-clicking.

Note: Assisted import matches each row to existing records and shows Create / Update / No changes / Flagged before commit.

If fields are updated, they will be highlighted so you know which fields are being updated before completing the import.

7. Import

Click on the Import button
The data is added to Katana.
1. Processing happens in the background and completes quickly, even for larger files.

How stock works

One row is one unit

Each serial number in the file is one unit of stock at its location. A serial number already in stock where the row says, is left as it is (or only its expiry date changes). Importing the same file twice changes nothing the second time.

Units without serial numbers

An item can hold stock without serial numbers, typically all of its stock when serial number tracking has just been turned on. The import can assign serial numbers to those units instead of adding new stock.

Cost

The file has no cost column. Giving serial numbers to existing units doesn't change their value.

Good to know

A serial number belongs to an item. Two different items may each have a serial number SN-1; the same item can't have it twice.
One row per serial number. If the same serial number appears twice for the same item in a file, both rows are skipped, so the customer keeps the one they mean. sn-1 and SN-1 count as the same.
Never moved. A serial number in stock at another location is skipped with Already in stock at Warehouse B (the location's name). Moving it is a stock transfer, done in Katana.
Never double-counted. A serial number expected on an open purchase or manufacturing order, or reserved on a sales order without being in stock, is skipped: importing it now would count it twice once the order arrives.
Blank expiry keeps what's there. A blank expiry date never clears one; the import can't remove an expiry date.
Dates: year first (2027-06-30) always works. Day-first or month-first dates are read when the column makes the order clear. A date Katana can't read is ignored with a note, and the rest of the row imports.
Users who can't see every location. To such a user, a serial number Katana knows but holds in no location they can see may be in stock where they can't look, so it's skipped with Already known to Katana — possibly in stock at a location you can't access, and they aren't offered to add serial numbers back. Rows for a location they can't access are skipped. Someone who can see every location should run imports that add serial numbers back.
Turning on tracking from the import works for products and kits. Items that track batches can't be switched here. Materials can be switched where Katana lets materials track serial numbers; otherwise the page says … is a material, and materials can't track serial numbers yet. Services hold no stock and are skipped.
One stock import at a time. If another import that changes stock is running for the account, the import is refused with Another import that changes stock is already running for this account. Wait for it to finish before starting another.

Limitations

Limitation	Details
Row limit: 5,000 per import	For larger files, we recommend splitting the file into batches or use the template-based import. If the file is over the limit, the entire import will be rejected, there won't be a partial import.
Only the first sheet can be imported	If the spreadsheet contains multiple sheets, only the first sheet is read. We recommend moving all needed data to the first sheet or saving it as a separate file.
Existing items and locations only	Items and locations are never created.
No renaming or deleting	A changed serial number is read as a new one; serial numbers not in the file are left alone.
One stock import at a time	Shared with stock level imports for the same account.
Serial numbers	Not supported in Assisted import.
Can't be undone	To correct a mistake, import a file with the right values, or edit the batches in Katana.
Adds, never removes	The import puts serial numbers into stock or updates their expiry date. It never takes stock out or moves it between locations.
Expiry dates can't be cleared	A blank cell keeps the current date.

Common issues

Behaviour	Why?
A serial number shows in capitals	Katana stores serial numbers in capitals; the preview shows the stored value.
Leading zeros are gone	Excel removed them before upload. Format the column as text and save again.
An expiry date is struck through	Katana can't read it as a date. The row still imports without it.
Rows skipped for items without serial number tracking	Turn it on with the offer in Serial number stock options; the file is then checked again.
A serial number is skipped as already in stock at another location	The import doesn't move stock. Use a stock transfer.
No offer to add serial numbers back	The user can't see every location; someone who can should run it.
The item's total went up when the customer expected serial numbers on existing stock	The third answer was chosen. The first answer gives serial numbers to units already held.
The Import button is greyed out	The question is unanswered (Complete the serial number stock options above to import), serial number tracking is being turned on (Turning on serial number tracking…), or the preview is still loading (Working out what this file does to your stock…).
Re-importing shows everything as no change	The file is already applied. The button reads Nothing to import.

Your feedback is invaluable. Let us know your thoughts on this article or anything in Katana you'd like to see improved: [email protected]

How to import/update serial numbers via Assisted import