Hey. Recent British university graduate here. And I stutter. You have 3 options:  1) On the UCAS form itself, there is a space for declaring a disability - stuttering/stammering is on the list. You can tick that box if you'd like. Stammering is protected by the 2010 Equality act if you consider your stammer to negatively impact your day to day life. 2) Email the interviewer or whoever you've had correspondence with regarding organising the interview. You could potentially ask for extra time, if you feel you need it (I always ask for extra time for interviews). Or just say "Please could you let my interviewer know on the day that I have a stammer/stutter. I don't stutter because I'm nervous or unsure of what I'm saying. It's just the way I speak." If you wanted, you could request that the interviewer reads this beforehand: https://stamma.org/about-stammering/guides-non-stammerers/interviewing-people-stammer#block-contentfield-downloads.  Or option 3), just tell them on the day.  If I were you, I would email them to ask for extra time or questions beforehand (I believe they should not ask you for "proof" or a doctor's note, but I'm not entirely sure) and then additionally on the day, at the start of the interview, say to them: "Just before we start, it's really helpful for me to let you know that I have a stutter. I don't stutter because I'm nervous or unsure of what I'm saying. It's just the way I speak." Hope that helps!