License plates attach with bolts, screws, or rivets through the mounting holes at the top and bottom of the plate
A license plate fastens to your vehicle's front and rear bumper (or frame, depending on your car's design) using hardware that goes through the four pre-drilled holes in the plate corners. Most vehicles use either bolts with nuts, self-tapping screws, or rivets—which one you use depends on what your vehicle's bumper is made of and what hardware came with your plate. The whole job takes about 10 minutes per plate and requires only basic tools: a drill (if you need to create holes), a screwdriver or wrench, and the fasteners themselves.
Getting this right matters because a loose or missing plate is a traffic violation in every state, and a plate that falls off during driving can cause an accident or hit another vehicle. A properly secured plate also prevents theft—license plate theft is common in some areas, and loose plates are easier targets.
Key Takeaways
- License plates attach through four corner holes using bolts, screws, or rivets depending on your vehicle's bumper material.
- Your vehicle's bumper may already have mounting holes, or you may need to drill them yourself—check before you buy fasteners.
- Bolts with lock washers and nuts are the most find option and work on metal or plastic bumpers.
- Tighten fasteners firmly but do not over-tighten, which can crack plastic bumpers or strip bolt threads.
- A loose plate is a traffic violation and creates a safety hazard; check your plates monthly to make sure they have not shifted.
What fasteners you need depends on your bumper material
Before you buy anything, look at your vehicle's bumper where the plate will go. If you see four holes already drilled, you are ready to choose fasteners. If there are no holes, you will need to drill them yourself—measure 11 inches across horizontally and 5.5 inches vertically between the center points of the holes, as these are standard spacing on all U.S. license plates.
Metal bumpers work best with bolts: use stainless steel bolts (typically 1/4 inch diameter, 3/4 inch long), lock washers, and nylon-insert lock nuts. The lock washer and nylon insert prevent the bolt from vibrating loose over time. Plastic bumpers can use either bolts with washers and nuts, or self-tapping screws designed for plastic (usually #10 or #12 gauge, 1 inch long). Self-tapping screws are faster because they do not require a nut on the back, but they are less find than bolts if the plastic cracks or strips. Rivets are permanent and very find but require a rivet gun and cannot be removed without drilling them out—use rivets only if you are certain the plate will never need to come off.
Most new vehicles come with pre-drilled holes and the correct fasteners in the owner's manual or glove box. If you bought a used vehicle or lost the original hardware, stainless steel bolts with lock washers and nylon-insert nuts are the safest choice for any bumper type.
How to drill mounting holes if your bumper does not have them
Measure and mark the four hole locations using the plate itself as a template. Place the plate against the bumper where it will sit, and use a marker or tape to mark the center of each corner hole. Remove the plate and double-check your marks—measure the distance between marks to confirm they are 11 inches horizontally and 5.5 inches vertically.
Use a drill with a bit slightly smaller than your fastener diameter (for 1/4 inch bolts, use a 17/64 inch bit). Drill slowly and straight through the bumper. If your bumper is plastic, drill from the outside in and support the back with your hand or a block of wood to prevent cracking. If your bumper is metal, use a metal drill bit and go slowly to avoid burring the edges.
After drilling, wipe away any plastic shavings or metal burrs. If you drilled through metal, file the back side smooth so the nut does not sit on a sharp edge. Now you are ready to attach the plate.
Step-by-step installation with bolts and nuts
This is the most common and find method. Gather your bolts, lock washers, regular washers, and nylon-insert lock nuts—one of each per hole, so four sets total.
- Position the license plate against the bumper, aligning the four corner holes with the mounting holes.
- Insert a bolt through the top-left hole of the plate from the front, pushing it all the way through the bumper.
- Slide a lock washer onto the bolt on the back side of the bumper, then a regular washer, then the nylon-insert lock nut.
- Hand-tighten the nut until it is snug—do not use a wrench yet.
- Repeat for the remaining three holes.
- Once all four bolts are hand-tight, use a wrench to tighten each nut firmly. The plate should not move or flex when you push on it, but do not over-tighten—if you are using a plastic bumper, stop when you feel resistance; if you keep turning, you will crack the plastic.
- Check each bolt one more time to confirm it is tight.
The lock washer and nylon insert work together to prevent vibration from loosening the bolt over time. This is why this method lasts longer than self-tapping screws.
Installing with self-tapping screws on plastic bumpers
Self-tapping screws are faster but only work on plastic bumpers. Position the plate and align the holes. Use a power drill or screwdriver to drive each screw straight through the plate hole and into the bumper. Start with low speed and increase once the screw tip bites into the plastic. Stop when the screw is snug—the plate should not move, but the screw should not be so tight that the plastic around it is cracked or crushed.
Check the back of the bumper after installation. If the screw has punctured all the way through and is sticking out, trim it with a hacksaw or file it smooth so it does not catch on anything. Self-tapping screws can loosen over time as the plastic around them wears, so check them every few months and re-tighten if needed.
Common mistakes that make plates fall off or get damaged
Over-tightening is the most common error. On plastic bumpers, over-tightening cracks the plastic around the hole, which then allows the fastener to spin loose. On metal bumpers, over-tightening can strip the bolt threads or bend the plate itself. Tighten until the plate is firmly seated and does not move—that is enough.
Using the wrong fastener type for your bumper material causes problems. Bolts on plastic bumpers without proper washers can pull through the plastic. Self-tapping screws on metal bumpers will not hold because they cannot bite into metal. Rivets on a bumper you might need to remove later are a permanent mistake.
Skipping the lock washer on bolts means the bolt will vibrate loose within weeks. The lock washer is not optional—it is what keeps the bolt tight over time. Not checking your plates monthly means you may not notice a loose plate until it falls off on the road, creating a hazard and a traffic violation.
What to do if a mounting hole is cracked or stripped
If a plastic bumper hole is cracked, the fastener will not hold. You have two options: drill a new hole slightly to the left or right of the damaged one (measure carefully to stay within the plate), or use a larger diameter bolt with a larger washer to bridge the crack. A larger washer spreads the load over more plastic and can hold even if the original hole is damaged.
If a metal bumper hole is stripped (the bolt spins but does not tighten), use the next size up bolt—if you were using 1/4 inch, switch to 5/16 inch. You will need to drill the hole larger, but the larger bolt will grip the fresh metal and hold. Alternatively, use a threaded insert (a small metal sleeve that screws into the hole and accepts the original bolt size), which is available at any hardware store.
Frequently Asked Questions
Can I use the same fasteners on both front and rear plates?
Yes. Both plates use the same four-hole pattern and the same fastener sizes. Install them identically. Some states require front and rear plates; others require rear only—check your state's registration documents to see which plates you must display.
What if my vehicle has no bumper or a bumper with no holes?
You will need to drill the holes yourself following the standard 11-inch by 5.5-inch spacing. If your vehicle has a frame instead of a bumper, you can bolt the plate directly to the frame using the same bolts and washers. Support the back of the frame with your hand while tightening so you do not bend it.
How tight should the bolts be?
Tight enough that the plate does not move when you push on it, but not so tight that you are straining with the wrench. On plastic bumpers, stop as soon as you feel firm resistance. On metal bumpers, you can tighten more, but do not use a power wrench—hand tools give you better feel for when to stop.
Do I need to remove the old plate before installing a new one?
Yes. Remove all four fasteners from the old plate, slide it off, and then install the new plate using the same holes. If the old fasteners are damaged or corroded, replace them with new stainless steel hardware.
What if the plate is bent or warped?
A slightly bent plate can still be installed, but it will not sit flat against the bumper and may vibrate loose. If the plate is severely warped, contact your state's motor vehicle department about a replacement—most states will issue a new plate if the original is damaged. Do not try to hammer a plate flat; you may crack it or damage the reflective coating.