Customers Purchasing Out-of-Stock Variants in WooCommerce Store – Seeking Help

Hello Everyone,

I’m currently facing a recurring issue in a WooCommerce store that I cannot explain. Users are purchasing items that are currently out of stock.

Background: We are a service provider managing a WooCommerce store for one of our clients. For some products, we have added additional variants where we offer items in a different quality condition (e.g., used). We manage the available quantities via the WooCommerce REST API. Additionally, the store is connected to Billbee, which handles the stock of the “classic” variants. Our variants are set up as normal variants in the shop with the following settings:

Product Data:

• Variable Product
• Stock Management Disabled at the Product Level

Product Data > Variants (see also the response from the REST API):

• “Manage Stock?”: Enabled
• Stock Quantity: 0
• “Allow Backorders?”: Do Not Allow

The Issue: From our logs, shop display, the REST API, and Billbee, I have confirmed in several scenarios that the stock was at 0, yet a customer could purchase this variant, causing the stock to drop to -1. I cannot replicate such a purchase myself, as I always receive appropriate messages in the shop on the product detail page: “Out of stock” and “This product is unavailable. Please choose a different combination.” when trying to add it to the cart.

My Thoughts: Could it be possible if JavaScript is blocked or if the item is displayed as available through Google/other search engines? Has anyone encountered a similar issue before? Is there anything I might have missed checking? Any help would be greatly appreciated, and feel free to reach out with any questions.

Best regards,

Jonas

RestAPI Get response “/wp-json/wc/v3/products/95799/variations/159355”

{ …

“manage_stock”: true,

“stock_quantity”: 0

“stock_status”: “outofstock”,

… }