I knew I had established myself as a trusted advisor to the CEO when the conversations started happening before decisions were made, rather than after decisions were made and HR was being asked to implement them.
For me, the single most important characteristic in earning that trust has been independent judgment.
A CEO does not need another person who automatically agrees or reflexively challenges. They need someone who can assess what is best for the enterprise, understand the pressures surrounding a decision, and offer a perspective that is thoughtful, candid and grounded in the broader business.
That sometimes means supporting the CEO's direction. Other times it means asking a difficult question, challenging an assumption or raising a risk that may not yet be getting enough attention. The goal is not to prove that I am right. The goal is to improve the quality of the decision.
I have also learned that candor alone does not make someone a trusted advisor. Without judgment, candor can simply become criticism. The harder skill is knowing which issues truly warrant executive attention, when to push, when to support, and how to bring a concern forward in a way that helps move the business toward a solution.
The most useful loyalty I can offer a CEO is loyalty to the enterprise and its long-term health. When a CEO knows that your advice is coming from that place, the relationship changes.
Being close to the CEO does not make you a trusted advisor. Being trusted to exercise independent judgment does. The goal is for the CEO to know that whether I agree, challenge or ask another question, my advice is coming from the same place: what I believe is best for the enterprise.