This is the reference table nobody publishes. Every product type handles inventory differently, and the behavior isn’t always what you’d expect.
| Product Type | Tracks Stock? | How It Works | Watch Out For |
|---|---|---|---|
| Simple | Yes | Single quantity, decrements per order | Stock status can override quantity manually |
| Measured | With extension | Requires Measurement Price Calculator for decimal stock | Native WooCommerce doesn’t support decimal quantities |
| Grouped | Children only | No stock on parent; each child product has its own | Parent shows “out of stock” only when ALL children are |
| Variable | Per variation | Each variation has independent stock, SKU, price | Importing via CSV: orphaned variations if parent SKU is wrong |
| External | No | Not your inventory — links to external site | No orders or sales data generated in your store |
| Downloadable | Optional | Stock tracking available but rarely used for digital | Auto-complete can finalize mixed-cart orders prematurely |
| Add-Ons | No | Add-on options have NO inventory tracking | Cannot mark an add-on option as “out of stock” |
| Bundles | Per component | Each bundled product’s stock deducts independently | If one component sells out, entire bundle becomes unavailable |
| Composite | Per selection | Stock deducts based on customer’s component choices | Complex composites can have availability race conditions |
| Subscriptions | Per renewal | Each renewal creates an order that deducts stock | Renewal failures if subscription product goes out of stock |
| Memberships | N/A | Access control system — not a physical product | Discount stacking with sales + coupons can be unexpected |
| Bookings | Capacity-based | Availability by time slot and resource, not traditional stock | Timezone mismatches between operator and customer |
| Content Drip | N/A | Digital access — no physical inventory | Refund → access revocation may not be automatic across LMS + Woo |
| Print on Demand | Effectively no | Products always “in stock” — POD provider manufactures on demand | Returns have no clean flow; label points to your address, not POD facility |
| Marketplace | Vendor-managed | Each vendor manages their own stock in their dashboard | No cross-platform sync; vendors must maintain accuracy manually |