Which one is correct: "personal basis" or "individual basis"? I want to use it in a formal letter. I want to say: "I don't know Mr. X on a personal basis (or individual basis) and I have not had an opportunity to work with him". I want to avoid saying "I don't know Mr. X on personally". In fact, I am looking for an equivalent phrase for the adverb "personally".
Could someone help me?