This plugin adds an age check to the checkout form. Customers have to tick a box in order to be able to place an order. 
You can customise the messages and enable/disable the function from the Woocommerce settings page. 
Works like a charm with WordPresss 5.3 and the latest versions of Woocommerce.

Age Checkbox for-Woocommerce

This plugin adds a customisable age check to the checkout form. Customers have to tick a box in order to be able to place an order.

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WooCommerce Age Validation Per Product gives you fine-grained control over who can purchase restricted items in your WooCommerce store based on date-of-birth (DOB) settings. Shop owners can: 
* Set a minimum or maximum DOB on simple products. 
* Globally define DOB restrictions for variable products, or set them per variation. 
* Prompt users for DOB at checkout only if restricted items are in the cart. 
* Block checkout if the entered DOB does not satisfy the product(s) restrictions.
Key Features: 
* Per-product or per-variation DOB range (e.g., only allow customers with birthdates in 01-01-1980 to 31-12-2005). 
* Global fields for variable products that override each variation’s settings. 
* Conditional DOB field at checkout (shown only if restricted items are in the cart). 
* Client-side datepicker in the admin (so store managers can pick min/max dates) and in the checkout for users. 
* Automatic validation to block purchase if the DOB is outside the allowed range. 
* Optionally show notices on the product page or in the cart for restricted items.
Use Cases: 
* Alcohol, tobacco, vaping, or adult content requiring age gating. 
* Specialty products requiring a specific DOB range (e.g., child tickets vs. adult tickets). 
* Special subscription products that require age segmentation (i.e. summer camps for children of different ages). 
* Any scenario needing a user’s date-of-birth for compliance.
<h3>Usage</h3>
<ol>
<li>Activate the plugin. </li>
<li>For Simple Products:
<ul>
<li>Go to the “General” tab in “Product Data,” fill in DOB Minimum or DOB Maximum in <code>dd-mm-yyyy</code> format. </li>
</ul>
</li>
<li>For Variable Products:
<ul>
<li>In the “General” tab, fill in Global DOB Minimum or Global DOB Maximum. </li>
<li>(Optionally) Edit each variation to set specific DOB fields if the global fields are empty or need overriding. </li>
</ul>
</li>
<li>Optionally adjust JavaScript to handle date format or display if your store uses different date formats. </li>
</ol>
If you have any questions, see the “FAQ” section or contact us at https://socialmind.gr/contact.

Age Validation Per Product for WooCommerce

Validate and enforce age restrictions per product or variation in WooCommerce, with user profile storage.

Age Checkbox for-Woocommerce vs Age Validation Per Product for WooCommerce