Are License Plate Frames Legal in Colorado?
Posted on August 12, 2026 by Plate Style
Yes, license plate frames are legal in Colorado. Two things make Colorado stricter than its reputation, and neither is about what the frame covers. The statute writes machine readability into the law — not human legibility, machine — and it tells you exactly where on the vehicle the rear plate has to sit, down to eighteen inches.
That second rule is the one nobody mentions, and it is the one that catches relocation brackets, tucked plates and roll-pan setups.
What the code actually says
C.R.S. § 42-3-202, "Number plates furnished to be attached", starts with placement — plates front and rear on a self-propelled vehicle, with rear-only categories listed separately. Subsection (2)(a)(II) then specifies the rear plate in detail. It must be:
"Horizontal at a height not less than twelve inches from the ground, measuring from the bottom of the plate"
"In a place and position to be clearly visible"
"Maintained free from foreign materials and clearly legible"
"At the approximate center of the vehicle measured horizontally"
"Mounted on or within eighteen inches of the rear bumper"
Five requirements, and the last two are dimensional in a way most states' codes are not.
The eighteen-inch rule
Almost every state says a plate must be securely fastened and legible. Colorado goes further and fixes its position: approximate horizontal center, and on or within eighteen inches of the rear bumper.
That converts several popular modifications from style choices into code questions:
- Side-mount and offset brackets. A plate mounted to one side of the bumper is not at the approximate center measured horizontally.
- Tucked and roll-pan mounts. Usually fine on distance — they sit right at the bumper — but frequently fail the 12-inch minimum height once the car is lowered.
- Hitch-mounted and cargo-rack plates. These are the ones that run past eighteen inches from the bumper on a long carrier.
- Angled mounts behind a bull bar or winch, which fail "horizontal" independently of anything else.
None of that has anything to do with the frame you bolt on. It is worth checking anyway, because it is the part of this section with an actual number attached.
Machine readability is written into the statute
Subsection (2)(b) is where Colorado gets modern:
"A person shall not operate a motor vehicle with an affixed device or a substance that causes all or a portion of a license plate to be unreadable by a system used to automatically identify a motor vehicle."
The same subsection lists what counts, "without limitation": a cover that distorts angular visibility, alters the color of the plate, or is smoked, tinted, scratched or dirty so as to impair legibility.
Three of those five descriptions have nothing to do with whether you can read the plate standing behind the car. Distorts angular visibility is about off-axis performance. Alters the color is about the sheeting's optical behavior. Scratched describes a cover that is perfectly transparent and still scatters light. All three are describing a plate that looks fine to a person and fails for a camera.
That matters because a plate reader does not work the way your eye does. It illuminates in the near infrared and reads the retroreflective return from the plate's sheeting. A cover that adds a scattering layer kills that return without hiding a single character.
Two penalties, not one
Subsection (3) splits the consequences. A general violation of the section is a class B traffic infraction. A violation of the obscuring provision in (2)(b) is a class A traffic infraction carrying a fine of one hundred dollars.
That gap is the legislature ranking the offenses. Mounting your plate in the wrong place is untidy; defeating a plate reader is the thing they wrote a bigger number next to. If you are deciding what to risk, risk neither, but understand which one the state is actually aiming at.
What actually gets cited
- Tinted, smoked and "anti-photo" covers. The clear target of (2)(b), and the only item in this section with its own fine.
- Scratched or yellowed clear covers. Explicitly listed. A cover that was fine when new is not fine after three summers.
- A dirty plate. "Maintained free from foreign materials" in (2)(a)(II) is a positive duty, and Colorado winters supply the material.
- Relocation and hitch mounts that break the center, height or eighteen-inch rules.
- A frame heavy enough to cover characters. Not named separately, but it fails "clearly legible" and "clearly visible" at once.
Test yours before you drive
- Measure three things: ground to the bottom of the plate (at least twelve inches), bumper to plate (no more than eighteen inches), and the plate's offset from the vehicle's centerline.
- Photograph the plate straight on from thirty paces, then from 45 degrees each side — "distorts angular visibility" is an off-axis test.
- Shoot one frame at night with flash. If the plate blooms or the return looks dull, that is the retroreflective layer being interfered with.
- Remove any cover. Given how (2)(b) is written, there is no cover that clearly survives it.
- Check the front plate too. Colorado requires plates front and rear on self-propelled vehicles, and the front one is easy to forget.
Picking a frame that passes in Colorado
Because Colorado's obscuring rule targets devices and substances on the plate rather than the surround, a slim frame is straightforwardly fine — provided it clears the printed area, leaves the decal corners open, and does not sit proud enough to throw a shadow or a reflection across the plate face at an angle.
Ours are cut from 3 mm cast acrylic with a slim profile and standard US mounting slots, with any lettering on the bottom bar rather than over the plate, and nothing that lies on the plate face. See the range in license plate frames, compare states in license plate frame laws by state, and for the machine-readability argument in more depth see are glow-in-the-dark license plate frames legal.
Frequently asked
Are license plate frames illegal in Colorado?
No. Section 42-3-202 does not mention frames. It requires the plate to be clearly visible and legible, and separately prohibits devices and substances that defeat automatic plate readers.
Are tinted license plate covers legal in Colorado?
No. "Smoked, tinted" appears verbatim in the list of prohibited covers in subsection (2)(b), and a violation is a class A traffic infraction with a hundred dollar fine.
Does Colorado require a front plate?
Yes for self-propelled vehicles — the statute attaches plates front and rear, with specific categories listed as rear-only. Both plates are subject to the same legibility rules.
Is a tucked or relocated plate legal?
Only if it still meets all of the position rules at once: horizontal, at least twelve inches off the ground, at the approximate horizontal center, and on or within eighteen inches of the rear bumper. Most tucked setups fail on height.
Can I be pulled over just for the frame?
An obscured or illegible plate is its own basis for a stop. A slim frame that covers nothing does not create one.
This article summarizes C.R.S. § 42-3-202 as published as of August 2026 and is not legal advice. The Revised Statutes are amended regularly and enforcement varies between agencies. Read the current section text and consult a licensed Colorado attorney about any specific citation.