Crossing the US Border with Kids (What Documents You Actually Need)

Crossing the US-Canada or US-Mexico border with a child involves more paperwork than crossing as an adult, especially if you're not the child's only legal parent. A US/Canadian birth certificate is usually enough for kids under 16 at land crossings, but a missing consent letter from the other parent can stop the whole trip cold. This guide covers what you need, what you should have, and what to do if you don't have it.

Verify before you travel. Rules for minors are enforced more strictly than rules for adults — officers have legal authority and a duty of care to investigate when something doesn't match up. The authoritative sources are CBP's WHTI FAQ and the Government of Canada's consent letter page.

The 30-second answer

Documents for kids — what works

At a land or sea crossing into the US, children under 16 can use just a US or Canadian birth certificate (original or certified copy). Passports work too but aren't required for under-16s.

This is a real exception in WHTI rules — adults need a passport, passport card, EDL, or trusted-traveler card, but under-16 kids get the birth-certificate-only path. Once they turn 16, the adult rules apply.

Special case: children 16-19 traveling as part of a supervised group (school trip, sports team, religious group, summer camp) can still use a birth certificate. This is mostly to keep field-trip logistics manageable; the group leader handles documentation on the bus.

At airports, even kids under 16 generally need passports for international flights. WHTI's "birth certificate works for kids" exception is for land/sea only.

Consent letters — when you need one

This is the single most overlooked piece of cross-border travel with kids. The principle: when a child is traveling without both legal parents/guardians, border officers want documented proof that any absent parent has consented. The rules:

• Both legal parents traveling with the child: No consent letter needed.
• One parent traveling with the child: Bring a notarized consent letter from the other parent (or a copy of any custody order showing you have sole legal custody, or a death certificate).
• No parents (e.g., grandparent, aunt, family friend): Bring a notarized consent letter signed by both parents (or sole legal guardian), plus copies of both parents' photo IDs.
• Separated/divorced parents with joint custody: Even with custody orders, both parents should ideally sign the consent letter. Carrying a copy of the relevant court order helps.

Neither country technically requires a consent letter by law, but officers have wide discretion to ask for one — and a missing letter can result in denial of entry or, more commonly, hours of secondary inspection while they verify the situation by phone with the absent parent.

What a consent letter should include

No specific format is required, but include all of:

• Child's full legal name, date of birth, and passport number (if applicable).
• Full name, date of birth, and current address of each parent or legal guardian, including the absent one.
• Full name, date of birth, and relationship of the accompanying adult (if any).
• Travel destination, dates of departure and return, and means of travel (driving, flying, etc.).
• Plain-language statement: "I, [absent parent name], consent to my child [name] traveling to [destination] with [accompanying adult name] from [departure date] to [return date]."
• Contact phone number for the absent parent — they may be called to verify.
• Signatures of all consenting adults, witnessed by a notary public.
• Attached copies of the consenting parents' government photo IDs (passport or driver's license).

Bring an original signed letter, not a photocopy or scanned PDF on your phone. Officers may not accept digital copies and are more likely to question their authenticity.

The Government of Canada publishes a free consent letter template you can use. It's drafted to satisfy both US and Canadian officers even though it's a Canadian document.

If you have sole legal custody

Bring a certified copy of the relevant court order showing your sole custody, plus the child's birth certificate. If the other parent is deceased, bring the death certificate. Without one of these, officers will often try to contact the absent parent before allowing the crossing — even if the parent has been absent for years.

If the custody situation is complicated (joint custody but one parent is unreachable, court orders in another country, etc.), call the CBP InfoLine (1-877-227-5511) or CBSA (1-800-461-9999) before you travel. They can flag your situation in advance so the officer at the border isn't seeing it cold.

Age-by-age summary

Infants under 1 year

Birth certificate sufficient at land crossings. No special rules beyond the consent-letter requirements if you're not both parents. Passport photos for infants are notoriously difficult, so if you have a choice, birth certificate is the easier path until they're older.

Toddlers and young kids (1-12)

Same rule — birth certificate works at land crossings. If they're in car seats and asleep, officers may briefly wake them to confirm the face matches the document. This is normal and not a sign of suspicion.

Tweens (13-15)

Still the birth-certificate rule, but most parents at this age have obtained a passport book for their kid anyway. Passport book is always accepted and removes ambiguity.

Teens (16-17)

Adult document rules apply: passport, passport card, EDL, or trusted-traveler card. Birth certificate alone is not enough. The one exception: 16-19 in supervised groups can still use a birth certificate.

18+

Treated as an adult in every way.

Practical tips at the booth

• Have everyone's documents ready before approaching primary inspection. Officers process more quickly when documents come out organized — child's birth certificate clipped to consent letter and parent IDs is gold.
• The driver answers questions for the whole vehicle. Don't pre-coach kids; just have the driver answer the standard questions. Officers may ask kids their name and where they're going as a basic verification — kids should know.
• Don't refer to "my friend's kid" or use unclear relationships. Be explicit: "This is my niece, traveling with me; her parents both signed the consent letter you have in your hand." Plain language with documents.
• If you're routed to secondary inspection, it's almost always for verification, not suspicion of wrongdoing. Be patient, answer questions, and let the process work. Most secondary inspections involving kids resolve within an hour.
• Time your crossing to off-peak hours if you can. Secondary inspections move faster when officers aren't slammed. See our best-time guide for the patterns.

Trusted-traveler programs and kids

NEXUS, SENTRI, and Global Entry all accept applicants of any age, including newborns. Applications for kids are free for under-18 applicants in NEXUS (verify the current rule before applying); for SENTRI and Global Entry, kids' applications have a reduced fee.

The catch: every occupant of the vehicle has to be a member to use the dedicated lane. If you have NEXUS but your toddler doesn't, you use the regular lane. So if you frequently cross with kids, enrolling them is worth the paperwork — and an under-18 NEXUS application is cheaper and faster than an adult's.

See our NEXUS application guide for the full process.

If you arrive without documents

US and Canadian citizens cannot be denied entry to their country of citizenship, even without documents. But the verification process for kids without papers can take 2-6 hours of secondary inspection. If you arrive at the border and realize you've forgotten the birth certificate:

1. Tell the officer immediately — don't try to bluff or use a health-insurance card as a substitute.
2. Be prepared to identify the child by phone call to the absent parent, to a school official, or to family doctor records.
3. If you have a passport for an adult traveler and the kid is on the adult's passport (some countries allow this), bring it out.
4. Expect a longer-than-normal wait. Travel with snacks and patience.

This is especially common for divorced parents who forget the consent letter when picking up a child mid-vacation. Plan ahead; carry the documents even if you don't expect to use them.

Bottom line

Under 16: bring the birth certificate. 16+: passport-equivalent document required. Single parent or accompanying-adult trips: bring a notarized consent letter from the absent parent(s), even if it's not legally required — the alternative is a multi-hour secondary inspection. And if there's a custody situation, bring the court order in writing.

Once everyone's papers are in order, find your crossing on the homepage to pick a low-traffic hour. Children travel better through 15-minute waits than 90-minute ones. For more documents background, see our main documents guide.