A few things to note: 1. Can you take these calls in a private room? The anxiety of what others in the room think of you may be a part of it. 2. Change in jobs and life situation has always brought on stuttering for me. With stability comes confidence, things will get better. 3. I’m not suggesting this long term, but some buffer words to get you started and keep conversation moving may not be the worst idea. Ahs, ums, “so”, etc., then day the word really slowly. 4. I have transitioned into a Job where I have to speak a lot, constantly. It’s actually been great for my confidence, although I have a long way to go. It’s a controlled environment, it’s “practice” and “maintenance” for me. It may not be the worst thing, hang in there. 5. Do you small talk with people you’re calling before getting down to business? Hi, how are you, things that are easy to say and get things moving before you talk shop. Good luck, hang in there, I’ve been there before, being embarrassed in front of my boss and co workers who don’t know WTF I am Doing and look at me like I’m ceazy or laugh. Fuck em. Prove them wrong with your competence in all other facets of the job. The better prepared I am, the less I tend to stutter. Attack this challenge aggressively.