Cheri, To enter Mexico you need picture ID (like a driver's license) and an official copy of your birth certificate. This copy must have an official seal on it. I always take another copy also but they won't accept a copy at the border. Also, if you name does not match you birth cert., then you need to take a marriage license. Now, sometimes when you enter they ask for nothing. other times they ask for alot. Remember, you also need to re=enter the US so have your documents!!!