Brands with out-of-stock products

By default, the Brands block and the Brands page only show brands that have products with a quantity greater than zero. If you want brands with products that are out of stock to be shown as well, you will have to make out-of-stock products visible in all sections. To do so, adjust the setting How to show out of stock products to "Show in all the sections"; the setting can be found in the Cart & Checkout settings of your store (Store > Cart & Checkout > Miscellaneous).

X-Cart 5.5.1.x and 5.6.x:

Note that enabling the option Show all for the setting How to show out-of-stock products in the Customer Zone settings will not only affect the display of brands but will enable the display of out-of-stock products throughout the store.