This message is automatically generated in Target's system (this could include Target.com, Target.com Direct Vendor Ship, or Target Canada) when they receive a Ship Notice without an SCAC that corresponds to a code they have stored in their system. This error might also be sent to you as "Your SCAC is missing/invalid," "SCAC Code Missing or Sent in a Invalid Format in the TD503," or "TD503 value is missing/invalid." All of these refer to the same issue. TD503 refers to the SCAC and SCAC stands for "Standard Carrier Alpha Code." This is an industry-wide standard four-digit code used to identify individual carriers (i.e. logistics providers) developed by the National Motor Freigh Traffic Association. These are the same four-letter codes that appear on shipping containers
Your logistics partner might be able to supply you with this code. Otherwise, these codes are generally available online. Wikipedia, for example, keeps a fairly up-to-date list of the most common of these codes. In Customer Operations at SPS Commerce, we have access to the official list of SCACs for all logistics providers, no matter how small. If you can't get a hold of the appropriate SCAC for your carrier, feel free to contact us and we will search the official database for it.