Fortunately, there's a much less risky solution available to you. You can:
1. Review the essential elements of your service agreement. Which aspects do you think need clarification? More importantly, which aspects does your client want to clarify?
2. Identify the unique service considerations that matter the most to your client. Then develop an action plan to address those and, in the process, clearly differentiate yourself from other service providers.
3. Agree on how you will communicate with each other. Make sure you know their requirements, as well as their preferences. One approach does not fit all.
There you have it. Building lasting client relationships is as straightforward as following these proven steps, but also as complicated since there are infinite possible variations within each element. Of course, you can just wing it and see how that works out, by simply assuming that you already have the answers. Just remember that the same things that got you hired can get you fired, so it's wise to figure them out before you have a problem.
In my experience, there's no better way to "clearly communicate that you're competent and you care", in the words of John Spence (aka "Trusted Advisor"), than by making the time for these important client conversations. You'll surely get greater satisfaction from your daily work and your client will absolutely appreciate you for it.