Hi, it is better to write: I am available for an interview at your convenience and can be contacted on xxx[insert your mobile number] Yours sincerely, Your name and surname.

hello Karen, to whom are you going to tell this? to the employer? point #1: I would suggest that you cut out the phrase "at your convenience" if you're going to say this to the employer. employing that phrase is unnecessary (employer can hold an interview any time at their will). point #2: If you really are dreaming of working to that particular company, then you should not ask them of your availability but rather, ask them directly when can you have the interview or better yet, tell them that you're free any time. Remember, it's you to adjust at their time and not them. point #3: you should always be ready and prepared for a job interview. in that case, I would also take out the "3-5 days notice in advance." I would rather say "I'm available for an interview any time." :)