diff --git a/htdocs/societe/class/api_contacts.class.php b/htdocs/societe/class/api_contacts.class.php
index f94e182b010..fc90f37e5bf 100644
--- a/htdocs/societe/class/api_contacts.class.php
+++ b/htdocs/societe/class/api_contacts.class.php
@@ -421,6 +421,48 @@ class Contacts extends DolibarrApi
         return $this->_cleanObjectDatas($this->contact);
     }
 
+    /**
+     * Remove the link between a category and a contact
+     *
+     * @url DELETE {id}/categories/{category_id}
+     *
+     * @param   int		$id				Id of contact
+     * @param   int		$category_id	Id of category
+     * @return  mixed
+     *
+     * @throws  401     RestException   Insufficient rights
+     * @throws  401     RestException   Access not allowed for login
+     * @throws  404     RestException   Category not found
+     * @throws  404     RestException   Contact not found
+     */
+    public function deleteCategory($id, $category_id)
+    {
+        if(! DolibarrApiAccess::$user->rights->societe->contact->creer) {
+            throw new RestException(401, 'Insufficient rights');
+        }
+
+        $result = $this->contact->fetch($id);
+        if( ! $result ) {
+            throw new RestException(404, 'Contact not found');
+        }
+        $category = new Categorie($this->db);
+        $result = $category->fetch($category_id);
+        if( ! $result ) {
+            throw new RestException(404, 'category not found');
+        }
+
+        if( ! DolibarrApi::_checkAccessToResource('contact', $this->contact->id)) {
+            throw new RestException(401, 'Access not allowed for login '.DolibarrApiAccess::$user->login);
+        }
+        if( ! DolibarrApi::_checkAccessToResource('category', $category->id)) {
+            throw new RestException(401, 'Access not allowed for login '.DolibarrApiAccess::$user->login);
+        }
+
+        $category->del_type($this->contact, 'contact');
+
+        return $this->_cleanObjectDatas($this->contact);
+    }
+
     // phpcs:disable PEAR.NamingConventions.ValidFunctionName.PublicUnderscore
     /**
      * Clean sensible object datas