How thresholds decide what gets blocked

A threshold is the minimum number of units you want to keep on hand for a variant. Easy Stock Buffer allows stock to fall to that number but blocks any checkout line that would take it lower, so your buffer is always protected.

How a line is judged

For each item in the cart, the app compares the quantity being bought against the stock available above the threshold. If buying that quantity would leave fewer units than the threshold, the line is blocked. In practice the units a shopper can buy equals current stock minus the threshold. A threshold of 0 means no protection for that variant.

Which threshold applies

A variant can be covered by more than one setting. Easy Stock Buffer always uses the most specific one, in this order:

1. A threshold set directly on the variant.
2. A bulk threshold for a collection, tag, or product type the variant belongs to (Pro).
3. Your shop-wide default threshold.
4. If none of those apply, the variant has no threshold and is never blocked.

Good to know

Thresholds only ever hold stock back - they never change your real inventory numbers in Shopify. To set one, see set a threshold on a product or apply one to everything with the shop-wide default threshold. The comparison itself is explained in how the checkout block works.