For a user trying to recover an account they think they own is more convenient if the questions are first; they should recognize the questions, or at least recognize if their correct answers were flagged as incorrect. For a user trying to keep their account secure, they would probably prefer a verification code first, since that effectively notifies them of attempts to access their account. Which is preferred? It likely depends on who you ask. I personally would follow the commented advice and ask on Security for the pros and cons of each. The actual experience to a legitimate user trying to access their account is relatively minimal, assuming you're going to require both steps anyways.