You can replace a license plate bulb yourself in most vehicles without tools or special knowledge

The bulb behind your license plate burns out like any other light in your car. Replacing it takes about 10 minutes and costs $3 to $15 for the bulb itself. You will need to access the housing from behind the plate—either from inside your trunk or from underneath, depending on your vehicle's design. Most cars use a straightforward twist-and-pull motion to remove the old bulb and snap in the new one.

The exact steps depend on whether your license plate is mounted on the trunk lid, the rear bumper, or the hatch. This guide covers the most common setup: a trunk-mounted plate. If your plate is on the bumper or hatch, the principle is the same, but you may need to reach from underneath or remove a trim panel first.

Key Takeaways

  • Most license plate bulbs are accessible from inside your trunk without removing the plate itself.
  • The bulb twists counterclockwise out of its socket and the new bulb twists clockwise back in—do not force it.
  • Buy the correct bulb type before you start; common sizes are 194, 168, or 921, and your owner's manual or the old bulb will tell you which one.
  • Test the new bulb with your headlights on before closing the trunk to confirm it lights up.
  • If you cannot reach the housing from inside the trunk, you may need to remove the license plate or access it from underneath the bumper.

Locate the bulb housing from inside your trunk

Open your trunk and look at the inner surface of the rear panel, directly behind where the license plate is mounted on the outside. You should see a plastic housing or a small rectangular compartment with two or four sockets protruding inward. This housing holds the bulbs for the license plate lights and sometimes the reverse lights as well.

If you cannot see the housing clearly, use a flashlight or your phone's light. The housing is usually black plastic and sits about 6 to 12 inches inward from the outer edge of the trunk. On some vehicles, you may need to remove a trim panel or carpet lining to access it fully. Check your owner's manual if the housing is not when ready visible—it will show you the exact location for your model.

Identify which bulb is burned out

The license plate housing usually has two bulbs side by side, one for each side of the plate, or four bulbs if your vehicle has lights on both the plate and the bumper. Look at both bulbs to see which one is dark or blackened inside. A burned-out bulb will have a broken filament or a dark coating on the inside of the glass.

If both bulbs look intact but one side of the plate is dark, the burned-out bulb may still look clear from the inside. In that case, turn on your headlights and have someone stand behind the car to tell you which side is not lighting up. Mark that socket with a piece of tape so you do not replace the wrong one.

Remove the old bulb and note its type

Grip the bulb firmly and twist it counterclockwise about a quarter turn. It should come free from the socket with gentle pressure—do not yank or force it, as the socket can crack. Once the bulb is out, look at the base. You will see a number printed or stamped on it: common sizes are 194, 168, 921, or 912. Write this number down or take a photo of the bulb before you set it aside.

If the number is not visible, check your owner's manual under "Bulb Specifications" or "Lighting." The manual will list the bulb type for license plate lights. You can also bring the old bulb to an auto parts store and ask them to match it. Do not guess—using the wrong bulb size can cause it to sit too loose, fall out, or not fit at all.

Buy and install the replacement bulb

Purchase a replacement bulb of the same type at any auto parts store, gas station, or online retailer. The bulb will cost between $3 and $15 depending on the brand. Some stores will install it for free if you buy it there; others charge $5 to $10 for installation. If you are comfortable doing it yourself, installation takes less than a minute.

Hold the new bulb by its plastic base, not the glass. Insert it straight into the socket and twist it clockwise until it stops—you should feel a slight click or resistance when it seats fully. Do not over-tighten; a firm quarter-turn is enough. The bulb should sit flush with the housing and not stick out or sit loose.

Test the bulb before closing the trunk

Turn on your headlights or ask someone to turn them on while you watch the license plate from behind the car. The newly installed bulb should light up brightly and match the brightness of the other side. If it does not light, turn off the headlights, remove the bulb, and check that it is seated all the way in the socket. Reinsert it and test again.

If the bulb still does not light after reinserting it, the socket itself may be damaged or corroded. In that case, you may need to have a mechanic inspect it or replace the entire housing. For now, close the trunk and drive to a shop during daylight to have it checked. Do not drive at night with a burned-out license plate light, as it is illegal in most places.

What to do if the housing is not accessible from the trunk

Some vehicles, especially older models or certain truck designs, have the license plate light housing mounted on the bumper or accessible only from underneath. If you cannot reach it from inside the trunk, you have two options: remove the license plate and access the housing from behind it, or crawl under the bumper to reach the socket from below.

To remove the plate, use a screwdriver to unscrew the bolts or clips holding it to the bumper—usually two bolts, one on each side. Once the plate is off, you will see the housing on the back of the bumper. The bulb removal and installation steps are identical: twist counterclockwise to remove, twist clockwise to install. After the new bulb is in and tested, reattach the plate with the same bolts.

Frequently Asked Questions

Can I use any bulb as long as it fits in the socket?

No. Using the wrong bulb type can cause it to sit loose and fall out, or to be too tight and crack the socket. The bulb number (194, 168, 921, etc.) is standardized, and you must match it exactly. Check your owner's manual or the old bulb to find the correct type.

What if the bulb keeps burning out after a few weeks?

A bulb that burns out repeatedly usually means the socket is corroded or the electrical connection is loose. Clean the socket contacts with a dry cloth or a small amount of electrical contact cleaner, then reinstall the bulb. If it burns out again, the wiring or socket may need professional repair.

Do I need to disconnect the battery before replacing the bulb?

No. License plate bulbs draw very little power and pose no shock risk. You can replace the bulb with the battery connected and the car off. There is no need to remove any fuses or disconnect anything.

Is it legal to drive with a burned-out license plate light?

No. Most states and provinces require all lights on your vehicle to be functional, including the license plate light. Driving with a burned-out plate light can result in a traffic citation. Replace the bulb as soon as you notice it is out.

What if I break the bulb while removing it?

If the glass breaks, carefully remove any remaining pieces with tweezers or a small tool, being careful not to cut yourself. Vacuum up any glass shards. Then install the new bulb normally. If the socket itself is cracked or damaged, you will need to have the housing replaced by a mechanic.