OP I would send a follow up thank you email for the telephone interview. I would also mention in a sentence that you have a stutter. Here is a guide from the National Stuttering Association’s guide for telling an employer that you have a stutter. Read this first OP first before you send that follow up email. https://www.westutter.org/post/stuttering-in-the-workplace OP good luck. I hope you are offered a position with this company. David