How will you establish your authority to a manipulative customer without being rude?

Hello Audrety,

This depends on the situation at hand, and what he is trying to manipulate. Even if he is manipulative in general each situation will be treated differently. Also what impact do this customer have on your project and/or engagement, short/long term relationship with his organization. What are you going to lose if you give in for him in one certain situation versus putting a strong stand and showing authority.

Most manipulative customers are like this for a reason, some wants just to get the best out of you with minimal cost possible i.e. abuse the situation and/or the relationship to the maximum. It is always smart way to handle such case by assuring him in each situation that you are walking extra mile with him, and please do so,  you can build trust with him and give him the sense that you will support him anyway he can because the success of this engagement is both yours and his and you need to work together to give it your best shot. After a while when you start to tell him this you can not do this or that, he will understand that it is really out of hand.

This is much better than showing authority to him. Win him first, build trust, show dedication and commitment then start saying no when it is absolutely necessary and even then give him another alternative that could be at least partially appealing to him.

Thanks and best of luck