# Update

### How to Use the Inventory Update Importer

#### Overview

The Import Inventory (update existing) tool lets you bulk update existing inventory items via CSV. It processes up to 1,000 records and generates a downloadable CSV report with results.

It can be found by navigating to the following page (Parts -> Import -> Import Inventory (update existing):

<figure><img src="/files/DJsMEvIJHoDxGqL3hcuu" alt=""><figcaption></figcaption></figure>

#### Step-by-Step Instructions

**1. Prepare Your CSV File**  
Create a file with these columns (all optional except as noted):

Required (at least one):

* Id — Inventory item ID (most specific; recommended)
* OR Part Number + some combination of Revision, Serial Number, Lot Number *(Not recommended - see* [*Known Issues*](/features/ion-importers/inventory/update.md#known-issues)*)*

Optional fields:

* Revision  
* Serial Number  
* Lot Number  
* Quantity  
* Quantity Scrapped  
* Unit  
* Location  
* Supplier  
* Cost  
* Custom attributes — Any custom fields configured for inventory (save for custom attributes of type File Attachment)

**2. Upload and Validate**

1. Click "Import Inventory (update existing)"
2. Upload your CSV file
3. The importer validates each row as you type:

* Checks that the inventory item exists
* Validates that locations, suppliers, and units exist (if provided)
* Ensures quantity scrapped ≤ quantity
* Shows errors/warnings in real time

**3. Review Validation Errors**

Common errors:

* "No inventory found to update for this record" — Item doesn't exist or lookup fields don't match
* "There are no locations with this name" — Location doesn't exist; create it first
* "There are no suppliers with this name" — Supplier doesn't exist; create it first
* "There are no units with this type" — Unit type doesn't exist; create it first

**4. Submit the Import**

1. Fix any validation errors
2. Click through the importer workflow
3. Processing:

* Records are processed sequentially (one at a time)
* Large imports may take up to 8-10 minutes
* Only one import can run at a time

**5. Review Results**

After completion:

* A success message shows how many records were updated
* A CSV file is automatically downloaded with results:
* Success cases: Shows updated inventory IDs
* Failed cases: Shows inventory IDs and error messages
* Review the CSV to identify any failures (NOTE: in the case of some failures the inventory may have in fact updated - check the specific inventory in ION to check whether it updated prior to re-importing it)

#### Important Notes

* Partial updates: Only include columns you want to update
* Custom attributes: Custom fields are supported and will be updated if provided
* In the case of some failures the inventory may have in fact updated - check the specific inventory in ION to check whether it updated prior to re-importing it
* File size limit: Maximum 1,000 rows per import
* On occasion you may see an error toast pop up in the top lefthand corner during the update. These errors do not block execution of the update - the import will continue, and you will receive a CSV download at the end with all of the errors encountered during upload, as well as the associated part inventory ids.
* If you chose to include a column in the Excel file for upload, it's simplest to have a value in every cell, and have no empty cells (even if the value is not being changed from what it was before)
  * If the column type is a string (e.g. location, supplier, lot number etc), and a cell in the column is empty or blank, nothing will update in ION, even though some of those values (such as location) can actually be set to 'null' in ION.
  * If the column type is a number (like cost, quantity, quantity scrapped), the importer will interpret an empty cell as being a zero value and will set the value to zero in ION.
* Concurrent imports: Only one import can run at a time; if another is in progress, you'll see "Import already in progress" (NOTE: this should only be encountered rarely)
  * Only run bulk updates from a single tab

<figure><img src="/files/bnvaqGb0cJApuAAQfyRq" alt=""><figcaption></figcaption></figure>

NOTE: If you see the 'Import already in progress' display on a large upload, do not click away or re-import. The import is running in the background. When it completes, you'll see the UI with how many records were updated, as well as the CSV export to your downloads.

#### Known Issues

* Even though it looks as if the Part Number and Revision on an inventory can be updated through the importer, in reality they cannot - they are used exclusively to search for a part inventory in lieu of ID
* Updating boolean custom attributes may not behave as expected
* Updating datetime custom attributes in the importer only allows for a DD/MM/YYYY or DD/MM/YY format, and the timezone will be in UTC - not local
* The importer will let you update a part inventory found by Part Number + some combination of Revision, Serial Number, Lot Number (not by ID), even if multiple inventories exist. It will only update one of them, however. *For this reason it is recommended that this method of updating part inventories not be used.*
* (For gov-cloud customers) This importer makes use of a third party library called FlatFile. Table headers are sent to FlatFile's servers. Ensure no export controlled data is on headers.