Yes, anyone can do a name change. In theory, most states allow you to legally change your name by usage only -- meaning that you simply start using your new name without any court action, and at no cost.
However, practically speaking, because you don't have a marriage certificate, you will need an official court order changing your name before you'll get government agencies and many private companies, such as banks and title companies, to accept your new name.
Whether you have changed your name by usage or by court order, the most important part of accomplishing your name change is to let others know you've taken a new name. Although it may take a little time to contact government agencies and businesses, don't be intimidated by the task -- it's a common procedure.
The practical steps of implementing a name change are:
As long as you're changing to your new spouse's name, or returning to your old name, you can usually use the usage method to change your name after you get married or divorced -- you simply start using your new, or old, name. You'll need to provide proof of your name change, but showing your marriage certificate or divorce decree should be enough. However, if you want to change to a new name (for example, you and your new spouse are both taking on a name that's new to both of you, or you want a new name after a divorce) you'll have to get a court order. (For information on changing your name after marriage or divorce, read Nolo's articles Changing Your Name After Marriage or Changing Your Name After Divorce.)
Start by providing documentation that shows both the old and new names. If you've recently obtained a passport, it may be helpful because it can show your old name as well as the new name as an AKA ("also known as"). If you are stonewalled, you may want to gently but forcefully give a rundown of your state laws that support your position. (You can research the law for your state at Nolo's Legal Research Center.)
If the person with whom you are dealing remains uncooperative, ask to speak to a supervisor. Or, if you have trouble at the local office of a government agency, contact the main office. You have the legal right to change your name, even if the people you're dealing with don't know your rights.
If you have still a hard time getting an institution to accept your new name, you'll need to go to court and obtain a judge's order establishing your new name. It costs a few dollars in filing fees and will take a little time, but it's something you can easily handle on your own. Once you have a court order, you probably won't have any problem getting your new name accepted.
When you're ready to change your name, see the Nolo eForm Declaration of Legal Name Change, which you can use to change your personal records, identity cards, and other documents.
There are some restrictions on what you may choose as your new name. Generally, the limits are as follows:
If you're in California and you're looking for a step-by-step guide to getting your name changed, get How to Change Your Name in California by Attorneys Emily Doskow and Lisa Sedano (Nolo).