Merge Guest Order To Customer extension provide a feature to merge the guest order to already existing customer if the customer has used the same email id while placing an order as a guest. Magento has given feature to place an order as a guest for the customer even if he is registered. But If registered customer place an order as a guest then that order will not display in customer order list after login and It creates a problem for admin to see customer’s orders in his Manage customer section, to overcome this issue we come up with merge guest order with registered customer extension where If Registered customer place order as a guest then that after order place that order will merge with that customer and customer can see his order in his account. So Now customers don’t require to login to place an order as the order but even after the order place, he can see his order in his account.
With the help of this extension, If the Customer uses the same email Id in placing the order as a guest from which he is registered in your store. So after order placement, this extension will check if the order is placed as a guest then it will check If the customer already exists with that email id so it will set customer id for that order and set is_customer_guest to 0, So when the customer will log in he can see his order in his order list.