When you find out your spouse is cheating how long do you have to file for divorce?

This is up to you, if you wanted to end your marriage because he or she cheated. If this is the only way for you to move forward, just do it. You never know how much better it is to be divorce from your spouse. It will take you at least 9 months but sometimes it will take at least a year if there are settlement to make between man and wife.