We use serial numbers for many of our products. Our inventory in Acumatica is accurate as of date we went live. The problem is we sometimes need to process a return for sales completed in our old systems and Acumatica does not know about the serial numbers for those sales so we are unable to process the return in Acumatica as its asking for the serial number but when we enter them, the system does not accept it. So we are stuck and don't know how to process and create credit memos and generate serials for such returns.
Anyone knows best practice for handling this?