In order to protect your company from such situations, you can ask all your key employees to impose a non-compete clause. You can even make this agreement a mandatory part of your employment contract if you wish. A non-competition clause prevents staff from competing with you during or after your work. This prevents employees from entering markets or trades with you. No no. There is no legal or customary obligation for a non-competition clause to be notarized. However, it must be signed by the party against whom enforcement is sought in order to be enforceable. California, Montana, North Dakota and Oklahoma completely ban employees` competition bans. A non-competition clause prevents employees from disclosing valuable information (trade secrets).