Through a series of otherwise normal events, I placed an order with Amazon and received a confirmation email, but then I noticed that the order was nowhere to be found in my order history. The confirmation message didn’t have an order number, either — perhaps because the order was generated through Amazon’s Subscribe & Save program. And without an order number, I had no way to contact customer service to ask what happened.

Amazon usually does a good job with presenting consistent and complete order information in all the relevant places, but I guess one or two templates slipped through the cracks. My own experience confirms what seems like an obvious solution: give customers their order number as quickly and consistently as possible. If you show a confirmation page, put the order number there. If you send confirmation emails, make sure the order number is included. Otherwise, for the small percentage of orders that don’t show up properly in your system, you’re leaving customers without any reference point to use when they contact you.