How do i prove that i have lived in florida for more than three month?

You can write on the N-400 form the exact date that you move to your present address in Florida. At the time of interview, you can bring whatever evidence you have to prove the fact such as a rental agreement, and credit card bills showing that you have been shopping or gassing up in the state of Florida. You can also show many other items such as registering for classes or your children registering for classes, applying for a local library card, or for a Florida drivers license, etc. Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.