Shopify 'Inventory quantity can't be blank' and 'is not a number': the fix

Three small columns cause a cluster of inventory errors: "Inventory quantity can't be blank", "Inventory quantity is not a number" and its neighbours. They all come from the same group of related columns being half-filled. See the Shopify CSV import errors guide for the rest.

What it means

In the classic template, Variant Inventory Tracker, Variant Inventory Qty, Variant Inventory Policy and Variant Fulfillment Service work as a set. If the tracker names a system, the others must be valid. Shopify's current CSV documentation says the same about related columns: filling some and leaving others blank causes an error, and the message tells you which blanks need values.

Causes

1. Tracker set, quantity empty. Variant Inventory Tracker says shopify, Variant Inventory Qty is blank.
2. Text in the quantity cell, such as "in stock", "10 pcs" or "N/A".
3. A decimal or formatted number, such as 1,000 with a separator.
4. Wrong policy value, giving "inventory policy is not included in the list".
5. Blank fulfillment service while tracking is on.
6. A custom fulfillment service that has not been set up in the admin.
7. Columns shifted by an unquoted comma earlier in the row, so a value lands in the wrong column.

Broken row and fixed row

Broken:

Handle,Title,Variant SKU,Variant Inventory Tracker,Variant Inventory Qty,Variant Inventory Policy,Variant Fulfillment Service,Variant Price
tee,Tee,TEE-M,shopify,in stock,yes,,20.00

Fixed, tracking stock:

Handle,Title,Variant SKU,Variant Inventory Tracker,Variant Inventory Qty,Variant Inventory Policy,Variant Fulfillment Service,Variant Price
tee,Tee,TEE-M,shopify,25,deny,manual,20.00

Fixed, not tracking stock:

Handle,Title,Variant SKU,Variant Inventory Tracker,Variant Inventory Qty,Variant Inventory Policy,Variant Fulfillment Service,Variant Price
tee,Tee,TEE-M,,,,,20.00

Step-by-step fix

1. Decide whether you want Shopify to track stock for these products.
2. If not, clear the tracker, quantity, policy and fulfillment service cells on those rows.
3. If yes, set the tracker to shopify, enter a whole number in the quantity, use deny or continue for policy, and manual for fulfillment unless you use a service.
4. Remove text, symbols and thousands separators from quantities.
5. If you use a custom fulfillment service, create it in the admin first.
6. Check for shifted columns by counting fields on the failing line.
7. Re-import with overwrite ticked.
8. Open a product and confirm the quantity shows against the right location.

Prevention

Add data validation to the quantity column so only whole numbers can be entered. Keep a lookup of allowed policy values in the sheet. Build the four inventory columns from one source so they cannot drift apart. If stock changes often, plan to update quantities through your inventory system or Shopify's inventory tools, and use the CSV for product data only.

When to do it yourself and when to hand it off

For a small store with a single warehouse, the checks above are enough. Multi-location stock, supplier feeds that mix units and text, and regular stock refreshes are where things get fiddly. Our bulk product upload service formats inventory columns correctly at launch, and our monthly catalog work covers ongoing updates. A person reviews every output and you approve before anything goes live. You can try the free 10-product sample if your project is a fit.