Information support in kit preparation is critical for the design of efficient kitting systems. Existing literature is dominated by studies that address in-house kitting and order picking support in warehouse settings and that are based upon laboratory experiments. This study explores critical aspects of information support for kit preparation outsourced to partners in the supply chain based upon empirical evidence of a web application for kitting adopted in a real-life case of a manufacturer and a supplier. Detailed insights to kitting efficiency, information sharing and user acceptance are presented. Critical aspects are identified primarily related to the relationship and interaction between companies, quality of information sharing, usefulness, parts identification efficiency, and joint improvement and development efforts. This work highlights the importance of considering supply chain information sharing in outsourced kitting.