WooCommerce and Shopify handle inventory management differently enough that it's worth understanding the differences before migration — and making sure your stock levels transfer correctly. Here's a complete overview of how inventory works on each platform and how to migrate it correctly.

Key inventory differences: WooCommerce vs Shopify

Feature	WooCommerce	Shopify
Stock tracking	Per product or per variation, optional	Per variant, at specific location(s)
Multiple locations	Plugin required (WooCommerce Multi-Location Inventory)	Built-in (multiple locations)
Stock status	In Stock, Out of Stock, On Backorder	Available quantity, oversell allowed/not
Low stock alerts	Built-in (email when stock reaches threshold)	App or manual (no native low stock email)
Backorder management	Allow backorders setting per product	"Continue selling when out of stock"
Reserve stock on pending orders	Optional	Yes, reserved when order placed
Inventory history	Limited (manual adjustments logged)	Full history per variant (adjustments, sales, returns)
Draft orders inventory	Not reserved	Reserved when draft order created

Migrating stock levels correctly

Stock levels are among the most critical data to migrate accurately. An incorrect inventory count means either overselling (bad) or artificially low stock (lost sales).

WooCommerce stock structure

In WooCommerce, stock is stored at two levels:

Simple products: _stock post meta on the product post
Variable products with managed stock: _stock on the variation post (child of the product)
Variable products with parent-level stock: Stock managed at the parent product level, shared across all variations

Shopify stock structure

In Shopify, inventory is stored per variant at a specific location:

Each variant has an InventoryItem associated with it
InventoryItem has quantity at each location
When you create a product with a variant, Shopify creates the InventoryItem automatically
To set stock, you use inventorySetQuantities (GraphQL) or inventory levels endpoints (REST)

How migration tools handle this

Most migration tools (including k-sync) transfer the stock_quantity field from WooCommerce products and variants. When a product is pushed to Shopify:

The variant is created with inventory tracking enabled
Inventory is set at your primary Shopify location
If a variant had no stock_quantity in WooCommerce, inventory tracking may be disabled for that variant

What to check after migration:

Sample-check 10–20 products and compare stock levels between WooCommerce admin and Shopify admin
Verify that variable products with many variants all have correct per-variant stock
Check that out-of-stock products show as out of stock in Shopify (not as available with 0 quantity allowing sales)

Shopify inventory locations

If you operate from multiple locations (warehouses, retail stores, fulfillment centers), Shopify's multi-location inventory is a significant improvement over WooCommerce's plugin-based solutions.

Setting up locations before migration:

In Shopify Admin → Settings → Locations, add all your physical locations
Set a primary location for your main stock
Configure fulfillment routing (which location fulfills which orders)

After migration, you can move inventory between locations or adjust stock per location via:

Shopify Admin → Products → Inventory (bulk adjust per location)
Shopify API (inventorySetQuantities mutation)
Third-party inventory management apps (Stocky, Cin7, Brightpearl)

Overselling protection: "Continue selling when out of stock"

In WooCommerce, the backorder setting controls whether customers can purchase an out-of-stock product. The WooCommerce equivalent is "Allow backorders."

In Shopify, this setting is called "Continue selling when out of stock" on each variant:

Enabled: customers can buy even when stock is 0 or negative (equivalent to WooCommerce "Allow backorders")
Disabled: Shopify blocks add-to-cart when quantity reaches 0

After migration, verify this setting matches your WooCommerce backorder configuration. Many migration tools disable the option by default — check that products which previously allowed backorders still do on Shopify.

Low stock alerts on Shopify

WooCommerce sends automatic low stock emails when inventory drops below your configured threshold. Shopify does not have built-in low stock email notifications.

Options to replicate this on Shopify:

Stocky (free Shopify app): Inventory management with low stock reports and purchase order generation
LowStockAlert (free): Simple app that sends email alerts when stock drops below threshold
Shopify Flow: Available on Shopify and above plans. Create a workflow: "When inventory drops below X, send email to [your email]"
Third-party IMS: If you use Cin7, Brightpearl, or NetSuite, these handle low stock alerts with reorder workflows

Set up low stock alerts on day 1 post-migration — many stores go weeks without noticing stockouts because they forgot Shopify doesn't email like WooCommerce did.

Inventory management apps for Shopify

For stores that need more than Shopify's built-in inventory management:

App	Price	Best for
Stocky (by Shopify)	Free	Small-mid stores, purchase order management, low stock alerts
Inventory Planner	$99/mo	Demand forecasting, reorder planning
Cin7 Core	$349/mo	Multi-channel, multi-location, manufacturing
Brightpearl	Custom	Enterprise omnichannel inventory + order management
Katana	$179/mo	Manufacturing + inventory, production planning

Inventory audit after migration

Complete this within 24 hours of launch:

Export all products and stock levels from WooCommerce (before taking it offline)
Compare against Shopify inventory export (Products → Export → All products with inventory)
Fix any discrepancies via Shopify Admin → Products → Inventory (bulk edit)
Set up low stock alerts in your chosen app or via Shopify Flow
Verify "continue selling when out of stock" is correctly configured per product type
Test that purchasing an out-of-stock product behaves correctly (blocked or allowed, based on your settings)

Shopify inventory management after WooCommerce migration (2026)