It is especially needed for shipping companies more than us. When we ship an item, you start to be informed periodically about the status of your order (order completed, shipped or not, tracking number etc…) if your mail adress is wrong than you will not be notified about them. Sometimes we need directly and urgently ask you something with sms or whatsapp messages (if item is just finished in stock and if you want a replacement or refund etc) If we have your number, wee can contact you, if we do not, how can we? BUT ESPECIALLY SHIPPING COMPANY MAY WANT TO CONTACT YOU ABOUT DELIVERY. If they cannot contact you delivery will be harder sure. If you do not give that contact info correct and need help from us about delivery, we are close to those kind of wishes because we see such situations as deliberate attempts to mislead!