After testing car seats for over a decade, I can tell you that Washington state has one of the most comprehensive child restraint laws in the country. It requires rear-facing until age 2, a harness until age 4, a booster until 4’9", and the back seat until age 13 — covering every stage of a child’s growth.
Washington recorded 810 traffic fatalities in 2023, a 33-year high, with impaired driving involved in 48% of fatal crashes in 2024. More pedestrians and motorcyclists were killed in 2023 than in any other year on record. A properly installed car seat is your child’s best defense on Washington roads.
This guide covers every requirement of Washington’s child passenger safety law under RCW 46.61.687, from rear-facing seats through the booster seat transition.
Washington car seat laws by age
Rear-facing car seats: Washington law requires children up to age 2 to ride in a rear-facing car seat. This is a legal requirement, not just a recommendation, making Washington one of the leading states for rear-facing safety. Keep your child rear-facing as long as possible — ideally until they reach the maximum height and weight limits of their rear-facing seat.
Forward-facing car seats: Children ages 2 through 3 must ride in a car seat with a harness, either rear-facing or forward-facing. Washington law keeps children in a harnessed seat until their 4th birthday, providing extra protection during the years when a child’s body is most vulnerable in a crash.
Booster seats: Under RCW 46.61.687, children 4 and older who are under 4 feet 9 inches tall must ride in a booster seat. Unlike many states that use an age cutoff (typically age 8), Washington uses height as the sole criteria for transitioning out of a booster. This means some children may need a booster until age 10 or 12, depending on their height.
Seat belt: Once a child reaches 4 feet 9 inches tall, they must wear a seat belt. Washington’s seat belt law applies to all vehicle occupants regardless of seating position.
Back seat requirement: Washington law requires children under 13 to ride in the back seat whenever possible. This is a legal requirement — one of the strongest back-seat provisions in the country.
For help choosing the right seat for your child’s current size, check out our best-rated convertible car seats guide.
Fines and enforcement
Washington has significant penalties for child restraint violations:
The fine for a car seat or seat belt violation is $124.
Fine dismissal: If you present evidence within 7 days to the issuing jurisdiction that you have purchased an appropriate child restraint, the charge can be dismissed.
Washington has primary enforcement for child restraint violations, meaning officers can stop you solely for observing an unrestrained child.
Special situations
Taxis and rideshares: Washington’s child restraint law applies to all motor vehicles. Parents using Uber, Lyft, or taxis must provide appropriate child restraints. There is no rideshare or taxi exemption.
Vehicles without back seats: The back-seat requirement for children under 13 applies "whenever possible." If your vehicle has no back seat, children may ride in front with appropriate restraints. Never place a rear-facing car seat in front of an active airbag.
Leaving a child unattended: Washington law prohibits leaving a child under 16 unattended in a vehicle with the engine running, or a child under 12 unattended in a vehicle if conditions could be dangerous.
Crash replacement: Replace any car seat involved in a moderate-to-severe crash, even without visible damage. Many manufacturers offer free crash replacements, and insurance often covers the cost. See our guide on what to do with old car seats.
What to do if you get a ticket
If you receive a child restraint citation in Washington, here’s your action plan:
1. Purchase a car seat within 7 days to dismiss the charge. Washington law allows you to have the $124 fine dismissed if you show proof of purchasing an appropriate child restraint within 7 days of the citation.
2. Get a free or low-cost car seat. Washington has robust car seat assistance programs through local health departments, fire departments, and Safe Kids coalitions across the state. Visit our free car seats in Washington page for a complete list of resources.
3. Get your installation checked. Find a certified car seat technician near you through the NHTSA car seat inspection locator to make sure your seat is properly installed.
Frequently Asked Questions
When can my child stop using a booster seat in Washington?
Washington uses height instead of age — your child needs a booster until they reach 4 feet 9 inches tall. For some children, this may be age 8; for others, it could be age 10 or 12.
Does Washington require rear-facing car seats?
Yes. Washington law requires children under 2 to ride in a rear-facing car seat. This is a legal requirement with the $124 fine applying to violations. See our car seat safety basics for more on rear-facing safety.
What is the fine for a car seat violation in Washington?
The fine is $124. However, it can be dismissed if you show proof of purchasing an appropriate car seat within 7 days.
Does Washington require children in the back seat?
Yes. Children under 13 must ride in the back seat whenever possible. This is a legal requirement in Washington, not just a recommendation.
Are car seats required in Uber or Lyft in Washington?
Yes. Washington’s child restraint law applies to all motor vehicles with no rideshare exemption. Parents must provide their own car seat. Browse our safest car seat brands for travel-friendly options.
What makes Washington’s car seat law different from other states?
Washington is one of the most comprehensive states for child passenger safety. It requires rear-facing until 2, a harness until 4, a booster until 4’9" tall (no age cutoff), and the back seat until 13. Most states use age-based cutoffs instead of height.
