My client became a single member LLC in 2017; has filed Schedule C & No payroll up to today. Didn't intend to become S Corp.  He now wants to be classified as an S Corp starting  January 1, 2023.    Have read the instructions but is an unusual situation and I am not sure

a) if is possible after all these years  b) If his date of incorporation in Form 2553 will be 2017 and his election to be effective should be January 1, 2023  and/or   c) if writing Filed pursuant to Rev. Proc. 2013-30 should be included.  the one thing he really wants is to be an S Corp this year. 

Thank you very much