Is It Legal to Mount a Phone on the Windshield in California?

Yes, it is legal to mount a phone on the windshield in California, but only in two small corners of the glass and only if you use the phone hands-free once it’s there. California Vehicle Code Section 26708 bans attaching things to the windshield as a general rule, and Section 23123.5 creates the narrow exceptions that let a mounted phone be legal. Put the mount anywhere else on the glass, or pick it up to tap out a text, and you’re in ticket territory.

The Two Legal Windshield Zones

Section 26708(b)(12) lets a portable GPS device sit in the lower corner of the windshield on either side. Section 23123.5(c)(1) extends that same allowance to phones and other wireless devices, so they may be mounted “in the same manner” as a GPS.¹ That leaves you exactly two legal spots on the glass:

A five-inch square in the lower corner of the windshield on the driver’s side, measured from where the glass meets the dashboard and the side pillar. The mount has to sit outside the airbag deployment zone.²
A seven-inch square in the lower corner of the windshield on the passenger side.²

The center of the windshield, the area near the rearview mirror, and anywhere along the top strip are all off-limits. A mount in any of those spots violates the general obstruction rule in Section 26708.

One detail people underestimate: the entire setup has to fit inside the five- or seven-inch square, not just the screen. A phone in a bulky case on a suction arm can easily push past the limit on the driver’s side. Hold a ruler up to the whole assembly before you assume you’re clear.

Dashboard and Center Console Mounting

The windshield isn’t your only legal option. Section 23123.5(c)(1) also lets you mount the phone on the dashboard or the center console, as long as the placement doesn’t block your view of the road.¹ There’s no square-inch measurement written into the statute for dashboard mounts. The test is functional: can you still see the road clearly.

A dashboard mount sidesteps both the size limit and the airbag question. The trade-offs are a lower viewing angle, more glare in bright sun, and higher heat on the phone. If your car has forward-collision or lane-departure cameras near the top of the windshield, a dashboard mount also keeps the phone well clear of those sensors.

How You’re Allowed to Use It Once It’s Mounted

Placement is only half of the rule. Section 23123.5 also controls what you can do with the phone while you’re driving. You can’t hold it in your hand, even at a red light. The phone has to be set up for hands-free and voice-operated use.¹

There’s one narrow allowance for touching the screen: a single swipe or tap of one finger to activate or deactivate a feature. Tapping to start navigation or swiping to dismiss a call fits. Scrolling a playlist, typing an address, or holding the phone up to read a message does not. Emergency personnel in authorized emergency vehicles are exempt while on duty, and factory-installed systems built into the car are exempt as well.¹

Drivers Under 18 Can’t Use a Mounted Phone at All

The rules above apply to adult drivers. If the driver is under 18, Section 23124 bans the use of any wireless phone or electronic communication device while driving, full stop. Hands-free mode doesn’t cure it. A properly mounted phone with voice controls is still illegal for a minor behind the wheel. The only exception is a genuine emergency call to law enforcement, a fire department, or a health care provider.

What a Ticket Actually Costs

The base fine for a hands-free violation under Section 23123.5 is $20 for a first offense and $50 for each subsequent offense.¹ Those numbers are misleading on their own. California adds state and county penalty assessments, a court operations fee, a conviction assessment, a DNA fund surcharge, and an EMS penalty assessment on top. Once everything’s stacked, a first offense with a $20 base fine lands somewhere around $136 to $160 out of pocket.³ A second offense with a $50 base fine runs considerably more.

A windshield obstruction citation under Section 26708 is a separate infraction and is often written as a correctable “fix-it” ticket. Remove the obstruction, have an officer verify the correction, and you can avoid the fine. Ignore it and the assessments apply the same way.

The ticket isn’t the only cost. A distracted driving conviction can raise your California auto insurance premiums. Industry data suggests the average increase in California is around 43%, and the higher rate typically stays on your policy for about three years.

Staying Legal in Practice

A few checks before you drive off with a new mount:

Measure the whole rig, phone and bracket together, against a five-inch square for the driver’s side or a seven-inch square for the passenger side. Cases add more than you’d think.
Keep the driver-side mount outside the airbag deployment zone. Your owner’s manual shows where the side curtain and dash airbags deploy. A heavy mount in front of an airbag panel becomes a projectile in a crash.
If your phone and bracket won’t fit in the five-inch square, move to the dashboard. There’s no dimension rule there, only the requirement that your view stay clear.
Watch for cameras and sensors near the top of the windshield. A phone mounted too high or angled wrong can reflect light into forward-collision or lane-departure sensors and cause false warnings.
Set up navigation and audio before you start driving. Once you’re moving, a single tap or swipe is the only screen interaction the law allows.

1
California Legislative Information. California Code VEH 23123.5 – Driving Offenses
2
California Legislative Information. California Code VEH 26708 – Windshields and Mirrors
3
California Courts. Uniform Bail and Penalty Schedules