Car seat laws vary more than most parents expect, and Washington is no exception. Below are the current Washington requirements for rear-facing seats, forward-facing seats, boosters, and seat belts, verified against the official Washington State Legislature.
Law data last verified against official state sources: October 4, 2026.
Quick answer
Washington requires rear-facing under 2, a forward-facing harness seat under 4, a booster until the lap-and-shoulder belts fit properly (typically 8–12), and back-seat riding under 13 where practical.
Washington car seat requirements by age and size
| Stage | What Washington law requires |
|---|---|
| Rear-facing | Children under age 2 in a rear-facing child restraint system until the child reaches the seat’s manufacturer weight/height limit. |
| Forward-facing | Children under 4 (not rear-facing) in a forward-facing child restraint system with a harness until the manufacturer weight/height limit. |
| Booster seat | Children under 4′ 9″ who are not in a (a)/(b) restraint must be in a child booster seat until the vehicle lap and shoulder belts fit properly (typically ages 8–12). |
| Seat belt only | Age 8 (or 4′ 9″+). |
Fines and penalties in Washington
Fine: not published on the official state source. Note: the statute makes a violation a traffic infraction; the notice is dismissed if the person presents proof of acquiring an approved child restraint/booster seat within 7 days (first dismissal only).
Front seat rules in Washington
Front-seat rule: Drivers must transport children under 13 in the back seat positions where it is practical to do so.
The official law
- Statute: RCW 46.61.687
- Official source: Washington State Legislature
Washington car seat law FAQs
What is the fine for a car seat violation in Washington?
Fine: not published on the official state source. Note: the statute makes a violation a traffic infraction; the notice is dismissed if the person presents proof of acquiring an approved child restraint/booster seat within 7 days (first dismissal only).
When can my child stop using a booster seat in Washington?
Children under 4′ 9″ who are not in a (a)/(b) restraint must be in a child booster seat until the vehicle lap and shoulder belts fit properly (typically ages 8–12). Age 8 (or 4′ 9″+).
Does Washington law require rear-facing car seats?
Children under age 2 in a rear-facing child restraint system until the child reaches the seat’s manufacturer weight/height limit.
Can my child ride in the front seat in Washington?
Front-seat rule: Drivers must transport children under 13 in the back seat positions where it is practical to do so.
Where can I read the official Washington car seat law?
Statute: RCW 46.61.687 Official source: Washington State Legislature.
Check another state
Driving across state lines? Requirements change at the border — use our interactive car seat law checker to look up any state by your child’s age, weight, and height.
Related state guides:
This page is for general informational purposes only and is not legal advice. Child passenger safety laws change — always verify current requirements with your state’s DMV, highway safety office, or the official statute linked below before making decisions.