Window Tint Guide: Understand
Windshield Tint in South Carolina: The AS1 Line Rule
The windshield is the one window South Carolina treats most strictly. You cannot tint it to 27 percent like a side window. The statute allows film only as a strip along the top, and it ties the bottom edge of that strip to a small marking printed on the glass by its maker: the AS1 line.
That marking is easy to miss and often misunderstood. This guide explains what AS1 means under federal glass standards, how to find it on your windshield, what the strip may look like, and the narrow situations where more film is possible.
The short answer
South Carolina allows windshield film only along the top of the glass, and it may not extend below the AS1 line, a marking the glass maker puts near the top edge to show where the shade band ends. If no AS1 line is visible, no film may go on the windshield at all. The strip must be nonreflective and not red, yellow or amber, and it needs a certificate of compliance.
Key points
- Subsection (B) of S.C. Code § 56-5-5015 limits windshield film to the top, no lower than the AS1 line.
- If the AS1 line is not visible, the statute says no film may be applied to the windshield.
- AS1 is a federal glazing marking; below the shade band, windshield glass must pass at least 70 percent of light under federal standards.
- The statute sets no darkness number for the top strip, but it must be nonreflective and not red, yellow or amber.
- Clear heat-rejecting film over the whole windshield is not an exception under the statute's text; a medical affidavit is the only route it provides.
The rule
What the Statute Says About Windshields
Subsection (B) of S.C. Code § 56-5-5015 has three sentences. A sunscreening device must be nonreflective and may not be red, yellow or amber. A sunscreening device may be used only along the top of the windshield and may not extend downward beyond the AS1 line. If the AS1 line is not visible, no sunscreening device may be applied to the windshield.
Notice what is missing: there is no percentage. The 27 percent combined rule in subsection (C) covers side windows, and subsection (D) covers the rear-most window. For the windshield, the limit is about location, not darkness. The film may only occupy the top band, and everything below the AS1 line stays bare.
The definition of a sunscreening device in subsection (J) is any film designed to be used with the car's safety glass to reduce the effects of the sun. That covers dark visor strips and clear heat-rejecting films alike, which matters for people shopping for clear windshield film.
The marking
What AS1 Actually Is
Subsection (J)(11) defines AS1 as a glazing material position marking under the federal glass standard, 49 CFR 571.205, Standard No. 205. That standard requires car glass to meet ANSI/SAE Z26.1-1996, an industry standard it incorporates by reference, and requires glass makers to mark their glazing under section 7 of that standard. The subsection number the state statute cites now covers a different topic in the federal text, but the marking itself is still governed by Standard No. 205.
The point of the marking is light. In its 2012 rulemaking notice on Standard No. 205, NHTSA described the requirement that glazing in areas requisite for driving visibility pass at least 70 percent of light, and noted that the standard applies that level to the entire windshield except the shade band at the top and the area where the mirror or rain sensor mounts. The AS markings identify the type of safety glass, and on a windshield the AS1 line shows where the shade band ends. Below it is the clear-vision area the 70 percent requirement protects.
Standard No. 205 also clarifies how the marking is printed: an arrow sits within the AS letters, written in the form A arrow S1, with the base of the arrow next to a horizontal line and the arrow pointing toward the portion of the glass that meets the standard's Test 2. That line is the boundary South Carolina uses. Above it, a strip of film is allowed; below it, the glass stays bare.
Find it
How to Locate the AS1 Line on Your Windshield
Look at the upper corners
From outside or inside, check the top left and top right edges of the windshield for small printed text with the letters AS1 and an arrow, often near the black ceramic border.
Follow the arrow to the line
The arrow sits next to a short horizontal line. That line marks the lower boundary of the area where film may go.
Compare it with any factory shade band
Some windshields have a tinted band at the top from the factory. Do not use its lower edge as your guide; the statute names the AS1 line, not the band, so measure from the marking.
If you cannot find it, stop
Markings can be hidden behind trim, worn off or missing on some replacement glass. Under subsection (B), if the AS1 line is not visible, no film may be applied to the windshield.
The strip
What a Legal Visor Strip Looks Like
A legal strip runs across the top of the windshield and stops at or above the AS1 line. Because the statute sets no percentage for it, the strip can be darker than the side windows, but it still has to meet the rules in subsection (B) that apply to all film: nonreflective, and not red, yellow or amber. Mirror-finish or colored banners fail regardless of how high they sit.
A certificate of compliance is required for each window containing aftermarket film, and the windshield is a window. Expect the installer to place a certificate for the strip, just as for the side glass.
Watch the area around the mirror. Many windshields carry cameras and sensors for driver-assist systems near the top center, often surrounded by a black dotted border. A good installer works around those components and keeps the strip clear of any lens rather than cutting a straight line through them.
Clear film
What About Clear Heat-Rejecting Windshield Film?
Light ceramic films that are nearly clear are sold for windshields in some states because they block infrared heat and ultraviolet light while barely changing the view. Under South Carolina's text, they are still sunscreening devices, and subsection (B) still limits any sunscreening device to the area above the AS1 line. The statute contains no exception for clear or near-clear film.
The one route the law provides is the medical exemption in subsection (H)(1): a vehicle registered to a person with an affidavit from a South Carolina licensed physician or optometrist, kept in the car and renewed every two years. In a 2015 opinion, the Attorney General's office concluded that the exemption covers the placement of film as well as its darkness, which would include the windshield. That is an opinion, not a court ruling, so treat it as guidance.
A hydrophobic glass coating is a different product. It is applied to the outside of the glass to shed water, not designed as a film to reduce the effects of the sun, which is the statute's definition. If you are unsure how a product fits, ask before it goes on.
Why it matters
The Reason Behind the Rule
Standard No. 205 states its own purpose plainly: in part, to ensure a necessary degree of transparency in motor vehicle windows for driver visibility. The windshield is the window you look through for everything that matters at speed, from brake lights on I-85 to a pedestrian at dusk. Film below the shade band cuts the light that reaches your eyes at the moments you can least afford it.
For low-sun glare on morning and evening commutes, the legal tools are the strip at the top, the sun visor and good sunglasses. They work together, and none of them darken the part of the glass you need most at night.
| Product or situation | Allowed? | Why |
|---|---|---|
| Dark or light strip above the AS1 line | Yes | Subsection (B) allows film along the top, no lower than AS1 |
| Strip that extends below the AS1 line | No | Film may not extend downward beyond the AS1 line |
| Any film when no AS1 line is visible | No | Subsection (B) bars windshield film if the line cannot be seen |
| Clear heat-rejecting film over the whole glass | Not under the statute's text | It is still a sunscreening device, so the top-strip limit applies |
| Mirror-finish or red, yellow or amber strip | No | All film must be nonreflective and not those colors |
| Film below AS1 with a valid medical affidavit | Possibly | Subsection (H)(1); the Attorney General reads it to cover placement |
Plain-language summary of S.C. Code Ann. § 56-5-5015(B) and (H). Not legal advice; check with SCDPS or a lawyer for unusual cases.
Want a windshield strip done to the line?
We cut film for your vehicle, check where the AS1 line sits before anything goes on, and label every tinted window with the South Carolina certificate of compliance.
Common questions
How far down can a windshield tint strip go in SC?
No lower than the AS1 line printed on the glass. Subsection (B) of the tint law says film may be used only along the top of the windshield and may not extend downward beyond the AS1 line. There is no fixed number of inches in the statute, because the line's position depends on the windshield and vehicle.
My windshield has no AS1 marking. Can I still get a strip?
Not under the statute. Subsection (B) says that if the AS1 line is not visible, no sunscreening device may be applied to the windshield. Check both upper corners carefully, since the marking can be small or partly hidden by trim. If it truly is not there, the law leaves no room for a strip on that glass.
Is there a darkness limit for the windshield strip?
The statute does not set a percentage for the strip above the AS1 line. It does require every film to be nonreflective and not red, yellow or amber, and each tinted window needs a certificate of compliance. The 27 percent combined rule applies to the side windows and the rear-most window, not to the windshield strip.
Does a replacement windshield have an AS1 line?
Federal Standard No. 205 requires aftermarket replacement glazing to meet the standard and requires glass to be marked under it, so a proper replacement windshield should carry its markings. Check the corners after installation. If you cannot see an AS1 line, South Carolina's rule is simple: no windshield film on that glass.
Sources
- S.C. Code Ann. § 56-5-5015, South Carolina Legislature (https://www.scstatehouse.gov/code/t56c005.php), accessed October 2026
- 49 CFR 571.205, Standard No. 205, Glazing materials, eCFR (https://www.ecfr.gov/current/title-49/subtitle-B/chapter-V/part-571/subpart-B/section-571.205), accessed October 2026
- Federal Motor Vehicle Safety Standards; Glazing Materials, Notice of Proposed Rulemaking, 77 FR 37478 (June 21, 2012), NHTSA via Federal Register (https://www.federalregister.gov/documents/2012/06/21/2012-14996/federal-motor-vehicle-safety-standards-glazing-materials), accessed October 2026
- Opinion to Senator Luke A. Rankin on S.C. Code § 56-5-5015(H)(1), May 13, 2015, Office of the South Carolina Attorney General (https://www.scag.gov/wp-content/uploads/2015/05/Rankin-L.-OS-9832-FINAL-Opinion-5-13-2015-00643993xD2C78.pdf), accessed October 2026
- Ceramic Window Tint, LLumar / Eastman Performance Films (https://llumar.com/en/tint/ceramic/), accessed October 2026
Prices on this page are The Auto Show’s published starting prices. Film ratings and warranty terms come from the manufacturer. This guide explains South Carolina law in plain words; it is not legal advice.