About this plugin
This plugin stops customers from mixing different products in the same order. If a product is already in the cart, adding a different product will either be blocked, or the cart will be emptied first, depending on the option you choose. Different variations of the same product are treated as the same product, so they’re never blocked from sitting in the cart together.
This is useful for stores that sell a small number of standalone products or bundles that should never be combined with anything else in the same order, for example a single service booking, a made-to-order item, or a product with its own dedicated fulfillment process.
Once activated, go to WooCommerce > Settings > CartRules > One Product in Cart to turn the restriction on and choose what should happen.
Works with both the classic, shortcode-based cart and checkout, and the newer WooCommerce Cart and Checkout blocks.
Why upgrade to CartRules PRO?
This plugin only restricts the cart to one product at a time, for every product on the store. CartRules One in Cart PRO replaces it, and every other free CartRules plugin, with a single plugin that handles every rule type and gives you more control over how each one behaves.
Every rule type, in one plugin
- Category, tag, brand, shipping class, product type, any custom taxonomy, or individual products and variations, instead of installing a separate plugin per rule type.
- Unlimited rules, each with its own settings, managed from one screen: WooCommerce > Settings > CartRules > One in Cart PRO.
More control per rule
- Scope a rule to specific products or variations instead of “any one at a time” (for example, only keep one specific bundle separate, and let everything else mix freely).
- Choose what happens when a rule is broken: block the new product with a message, or empty the cart and add it, decided separately for each rule.
- Flags other cart restrictions already running on your store, whether from a free CartRules plugin or your own custom code, so two rules never silently conflict.
- Works with both the classic cart and checkout and the WooCommerce Cart and Checkout blocks.
Get CartRules One in Cart PRO →