Requirements

• Children under age 16 need a passport to travel to another country by air. This includes newborns. If you want to take your newborn abroad on a plane, you need to apply for a passport as soon as possible. However, this may not leave you enough time to receive a Social Security number for your newborn, which is usually required for U.S. passport applications.
  
  

Title 26

• According to Title 26 of the Internal Revenue Code, anyone applying for a passport needs to provide a Social Security number if they have one. However, since an infant may not yet have a Social Security number, that clause may make it easier for you to secure a passport for your newborn without providing an SSN. Title 26 says you may be exempt from the rule if it is determined you have provided enough other proof of your child's U.S. citizenship status.
  
  

Getting an SSN

• You can easily apply for an SSN after your baby is born, while filling out the birth certificate information in the hospital. There will be a box to check if you want to apply for an SSN. You can also apply for an SSN later by filling out an application, sending proof of your newborn's citizenship and age, and sending proof of both your and your child's identity. Getting an SSN is free; it can take up to nine weeks to receive your child's card, depending on where you live. If you wait to apply, it may take an additional 12 weeks to verify the birth.
  
  

Other Travel

• You do not always need a passport to travel with your newborn. You always need one when traveling out of the country by air, but not always if traveling by land or sea. For example, if you are crossing the Canadian border in a vehicle, you can simply provide your child's U.S. birth certificate as proof of citizenship.