Your child cannot ride in an Uber without a car seat as it is against the law in California, and both parents and the driver can receive citations as a result. However, it's important to note that Uber drivers typically do not supply car seats, which can create uncertainty for passengers.
For a dependable solution, you might want to consider using Airport Taxi Cab Services, which provides pre-arranged car seats. This company is owned by drivers and guarantees the availability of car seats while offering a fixed rate, eliminating concerns about price surges.