How to Change the Date of Birth on a Birth Certificate
If you need to change the date on your birth certificate, collect relevant documents to prove that the current date is wrong, like hospital records or a religious ceremonial record. If you can't get any of these, try to get hold of school immunization records. In case you don't have this option, you could try locating an application for social security, but bear in mind that these documents are less widely accepted. Then, contact your state's vital records office to confirm how to apply.
Talk with the hospital. While all states do not accept the same types of records to prove the date of birth, hospital records are the most widely accepted. If the date of birth on a birth certificate is incorrect, you should see if you can get a copy of the hospital records before you do anything else. In addition to copies of the original application for a birth certificate, the hospital should have records of the birth itself as a medical event. If the date on the application is incorrect, the medical records of the birth are the most credible document proving the date of birth. Ask your religious institution for baptismal or naming records. Another source of documentation for a particular date of birth is a religious record. In the US, this usually takes the form of an infant baptismal record. Baptismal records are better than no records, to be sure, but they aren't perfect. In Christian traditions, there is no set time limit dictating when an infant must be baptized. It may take place a few days after birth or a few weeks after birth. Indeed, some churches don't practice infant baptism at all. Records of Jewish and Islamic naming ceremonies tend to carry more weight; they prescribe the naming ceremony take place a certain number of days after the birth of the child. Collect school immunization records. If it has been a number of years since the birth of the child and you need to correct the date of birth, school immunization records are another widely accepted source of documentation. You should be able to retrieve these from your child's school. Since all children need to get immunized before they attend school—and because immunizations need to take place at particular intervals—school immunization records are regarded as fairly accurate. Find any other supporting documentation. Other documents are less widely accepted but are nonetheless acceptable in certain jurisdictions. For example, applications for Social Security numbers, insurance applications, or military records. Go to court if necessary. There is no standard procedure for obtaining a court order to change the date of birth on a birth certificate. The problem is unusual enough that most states do not have standard forms for filing that particular type of petition. Still, going to court is an option for anyone in this situation. You should try to get a court order to change the date of birth is none of the above documentation is available but you nonetheless have compelling evidence of the actual date of birth. For example, a video recording or photograph (with dateline) of the birth or the immediate aftermath of the birth. Since this is an unusual type of action to pursue in court, speak to a lawyer before you do it. If you cannot afford one, speak to a Legal Aid attorney in your state. Find your state's Legal Aid office at http://www.lsc.gov/what-legal-aid/find-legal-aid. Find the vital records office in your state. Even if you obtain a court order allowing you to modify the date of birth, you will still have to submit the court order (or any other documentation) to your state's department of vital records, which maintains birth and death records. In most states, vital records is under the umbrella of the state department of health. Fill out any necessary forms and submit all documentation. In some states, there are premade forms you can fill out to submit a change in a birth record. However, in many other states, there isn't. If you live in a state without a predetermined process for amending the birthdate on a birth certificate, you will have to call the vital records office up and ask about the process. As a rule, any documentation you submit should be in the form of a certified copy. Pay any fees. Typically, there are modest fees associated with amending birth records. They usually don't exceed $50, but you should be aware of it. While many governmental agencies now accept credit and debit cards as payment, most do not accept personal checks. Prepare to use cash, credit, debit, or a money order. 
Talk with the hospital. Ask your religious institution for baptismal or naming records. Collect school immunization records. Find any other supporting documentation. Go to court if necessary. Find the vital records office in your state. Fill out any necessary forms and submit all documentation. Pay any fees. 