Whether key card duplication is legal or not depends on the specific circumstances and applicable laws and regulations in the jurisdiction in question.
However, there may be situations where key card duplication is legal and permissible. For example, authorized personnel may be allowed to duplicate key cards for the purpose of providing access to new employees or replacing lost or damaged cards. In such cases, proper authorization and compliance with applicable laws and regulations would be necessary.
It is important to note that the legality of key card duplication can vary depending on the jurisdiction and specific circumstances involved. As such, it is always advisable to consult with legal counsel or seek guidance from the appropriate authorities before attempting to duplicate a key card.