Can my (already spent) set-up expenses from my personal bank account still be re

Hi – Having just set up an LLC, to date I only have a personal bank account. Can my (already spent) set-up expenses from my personal bank account still be recorded as business expenses at this stage? If I state that I am making $x contribution as a member, must that be the cash sum I put into a business checking account, or can it take into consideration any amount I have already invested using my personal account? Also, as I am in the UK and my business is in the US, would a Worldfirst account be recognised as a legitimate business checking account? Should I be putting in as much equity as I am comfortable with, or as little as I am comfortable with?
Thank you in advance.