A mother-son vacation sounds like simple, innocent fun, but in an age where bitter custody battles and child abduction are serious issue, it's best to make sure your legal bases are covered. Although domestic travel is unlikely to cause any problems – unless the issues is specifically mentioned in a custody agreement – an international trip with a child under 18 will likely require approval from both parents. The United States requires both parents, or legal guardians, to consent for a child to even get a passport, but mom's traveling alone with their sons might need to secure some extra documentation before their trip.

Permission Letter

Carry a letter of permission with you if you are traveling with a minor and both parents are not present, recommends Customs and Border Protection. Ideally the letter should be notarized. CBP staffers can ask to see the letter when you reach the United States border, and if you’re unable to show it, expect to be delayed while staffers investigate the circumstances of your travel. Border control in the country you’re traveling to might also have strict requirements, so check the State Department’s travel information for the country you intend to visit. Canada, for example, requires you present the letter before boarding a flight to the country, and you might be denied boarding if you cannot present it.

Suggested Wording

Although there is no specific standard wording for the permission letter, CBP suggests that the letter be worded along these lines: “I acknowledge that my spouse is traveling out of the country with my son. She has my permission to do so.” CBP also suggest you get the letter notarized to avoid any question of it being forged. Like a news report, the letter should contain the five W's about the trip: who, what, where, when and why. It’s also vital that the document provide contact information for the absent parent so staffers can follow up any queries.

Custody Disputes

If you are in a dispute with your husband over the custody of your son, you may not be able to travel internationally without his permission. However, if you have already been awarded sole custody, your husband has no legal claim on your son, so you don’t require his consent to travel. If this applies to you, you should carry a copy of the court’s decree confirming this. Some custody decrees specifically prevent either parent taking a child outside the United States. If you are in doubt, check the wording carefully.

Child Abduction

If your husband has a legal claim on your son and you travel internationally with him without first getting your husband’s permission, you could be considered guilty of child abduction. This is a crime in every U.S. state and in some cases is deemed a federal offense under the International Parental Kidnapping Crime Act. The potential seriousness of the offense underlines the need to gain permission before embarking on an international journey with your son.