Limit Cart Quantity

Mage2Expert Limit Cart Quantity is an extension for Magento 2 that gives store owners precise control over how many items a customer may carry in the shopping cart at any one time. Two independent limits can be configured — a minimum quantity (the customer must reach this count before proceeding to checkout) and a maximum quantity (the customer cannot exceed this count). Either limit can be left empty to disable that boundary entirely. Both limits can be overridden on a per-customer-group basis, making the extension ideal for B2B stores, wholesale portals, tiered pricing models, or any shop that needs differentiated purchasing rules for different types of shoppers. Validation is enforced at every touch-point — before an item enters the cart via AJAX add-to-cart, at cart-page rendering, at checkout navigation, and at order submission — so no loophole is left open regardless of how a customer attempts to bypass the limit. A styled notice is displayed on the cart page and the Proceed to Checkout button is hidden from both the cart page and the slide-out minicart whenever a limit is active, with all error messages fully customisable from the admin. The module is configured under Stores → Configuration → Magento Expert → Limit Cart Quantity and works with any theme without modifying a single Magento core file. 

Features

• Global Minimum Cart Quantity — set a minimum total item count that the cart must contain before the customer can proceed to checkout. When the cart falls below the threshold, the Proceed to Checkout button is hidden and a customisable error notice is displayed on the cart page. Leave empty to disable the minimum check entirely.
• Global Maximum Cart Quantity — set a maximum total item count allowed in the cart. Once reached, further add-to-cart requests are blocked and the Proceed to Checkout button is hidden. Leave empty to disable the maximum check entirely.
• Customer Group Quantity Overrides — configure independent minimum and maximum quantities for specific customer groups (Not Logged In, General, Wholesale, Retailer, or any custom group). A group-level rule takes full precedence over the global limits for every customer in that group; either boundary can be left empty in a group row to inherit the global value.
• AJAX Add-to-Cart Protection — when a customer clicks Add to Cart on a category or product page while the cart is already at the configured maximum, the request is intercepted server-side before the item enters the quote and a JSON error response is returned. The error message appears inline on the page without a full page reload, keeping the shopping experience fluid.
• Cart-Page Validation Notice — a dedicated validation-message.phtml template is injected at the top of the cart page via layout XML. When either a minimum or maximum limit is violated, a styled red "Cart Limit Reached" banner is shown with the customised error message. The notice is compiled from a LESS stylesheet and is visible in both Luma and Hyva-compatible themes.
• Checkout Button Control — the Proceed to Checkout button is hidden from both the cart page order summary and the slide-out minicart whenever the cart fails a limit check. Visibility is driven by a CSS class toggled reactively through Magento's customer-data KnockoutJS system — no page reload is required and the button reappears the moment the customer brings the cart into a valid state.
• Checkout Submission Guard — a final server-side validation fires at the checkout_submit_before event, blocking order placement if the cart still violates a limit at the moment of submission. This prevents any attempt to bypass the frontend checks by submitting the order directly.
• Multi-Shipping Checkout Protection — predispatch observers on both the multishipping_checkout_index and multishipping_checkout_overviewpost controller actions validate the cart limits and redirect back to the cart page with the error message if a limit is violated, applying the same enforcement to the multi-shipping flow as to the standard one-page checkout.
• Customisable Error Messages — the minimum and maximum error messages are fully editable from the admin. Each message supports a {{min_qty}} or {{max_qty}} placeholder that is replaced at runtime with the effective limit value for the active customer — whether from the global settings or a customer-group override — so the displayed figure is always accurate.
• Store-View Scope — every configuration field (Enable Module, Minimum Cart Quantity, Maximum Cart Quantity, error messages, and all Customer Group Quantity Limits rows) is independently configurable per store view. This makes the extension fully compatible with multi-store and multi-language setups from the start.
• Enable / Disable without Uninstalling — a master Enable Module switch in Stores → Configuration → Magento Expert → Limit Cart Quantity suppresses all cart quantity validation while leaving every configuration value and customer-group rule intact. Re-enabling the switch immediately restores full enforcement.
• Zero Core Code Modifications — built entirely on Magento's plugin, observer, and layout XML architecture. No class rewrites, no preferences, no patches to core files. Safe alongside Magento upgrades and third-party extensions.

How It Works

After installing the module and running php bin/magento setup:upgrade, navigate to Stores → Configuration → Magento Expert → Limit Cart Quantity. Set Enable Module to Yes and enter a value in Minimum Cart Quantity, Maximum Cart Quantity, or both. Save and flush the cache with php bin/magento cache:flush. The limits are active immediately: customers whose cart total falls outside the configured range will see the validation notice on the cart page and will not be able to proceed to checkout or place an order until the cart is within bounds. 

To configure per-group overrides, expand the Customer Group Limits section on the same configuration page and click Add Customer Group Limit. Select the customer group, enter the Min Qty and/or Max Qty for that group, and save. Group limits take effect immediately for any customer in the selected group and override the global values for that boundary only — leaving either field empty inherits the global setting for that boundary.

Use Cases

• Wholesale and B2B portals — require trade buyers to add a minimum number of items before they can check out, enforcing minimum order quantities without relying on product-level minimum qty settings that apply only to individual products.
• Flash sales and limited stock events — cap the maximum cart quantity to prevent a single customer from buying out the entire available stock, ensuring fair distribution across all shoppers.
• Tiered customer groups — grant Wholesale and Retailer groups higher cart maximums than General customers or guests, implementing purchasing tier rules without separate store views or complex catalog rules.
• Subscription box and bundle stores — enforce a fixed maximum to ensure customers select exactly the right number of items for a curated bundle, preventing over-selection before checkout.
• Marketplaces with fulfilment constraints — limit the number of items that can be shipped in a single order to align with warehouse or carrier constraints without modifying the core checkout flow.
• Multi-store setups — apply different minimum and maximum rules per store view for regional stores, wholesale portals, and retail sites from a single Magento installation with no additional configuration overhead