What is AIAG damage grading?

AIAG damage grading is a standardized way to describe vehicle damage developed in the automotive supply chain to keep condition assessments consistent across inspectors and locations. Instead of free-text notes like 'small dent,' it uses defined severity levels so the same damage gets the same grade no matter who's looking — which is what makes condition reports comparable and defensible.

What does the K1–K5 scale mean?

K1–K5 is a five-level severity scale for vehicle damage, running from K1 (minor, cosmetic) up to K5 (severe, structural or functional). Lower numbers are light wear that may be acceptable; higher numbers are significant damage that typically requires repair and recharge. Putting a number on severity is what turns a subjective 'is this bad?' into a consistent, comparable grade.

How does AI apply a consistent damage grade?

An AI inspection model is trained on graded damage examples, so it maps a photo to a severity level the same way every time — removing the inspector-to-inspector drift that plagues manual grading. The result comes back as a structured grade alongside the pass/fail criteria, so every vehicle is assessed against the same standard.

AIAG & K1–K5 Damage Grading Explained (With Examples)

If you've read a vehicle condition report and seen a damage entry tagged "K2" or "K4," you've met severity grading — and maybe wondered what the numbers actually mean. Standardized damage grades exist for one reason: to make condition assessments consistent across different inspectors, locations, and moments in time. "Small scratch" means something different to everyone; "K1" doesn't.

This is a plain-English explainer of the AIAG damage grading framework and the K1–K5 severity scale — what each grade means, with concrete examples — and how AI applies a consistent grade so the same damage gets the same number every time.

A note on positioning: VerifyAI leads with parking compliance, and vehicle damage inspection is a secondary capability. We publish this explainer because grading is foundational to defensible condition records, and the topic is poorly explained elsewhere.

Why standardized damage grading exists

Damage assessment used to be free text. One inspector writes "minor dent," another writes "noticeable ding," a third just checks a box. When those notes feed a rental dispute, a lease return, or a remarketing listing, the inconsistency is a problem: you can't compare two reports, you can't audit a pattern, and a customer can always argue the wording was subjective.

The automotive supply chain solved this with standardized grading — defined severity levels that mean the same thing regardless of who's assessing. The AIAG (Automotive Industry Action Group) is one of the bodies behind this kind of standardization, and severity scales like K1–K5 are how the standard shows up in practice. The point is comparability: a grade is a shared vocabulary that makes condition records consistent and defensible.

Grade ≠ opinion

The whole value of a grade is that it removes opinion. "That looks pretty bad" is an argument. "That's a K3" is a classification against a defined scale — the same input maps to the same output, which is exactly what you want when a charge is being disputed.

The K1–K5 severity scale, grade by grade

K1–K5 runs from minor to severe. The exact thresholds vary by program, but the shape is consistent — here's how to read each level, with examples:

K1 — Minor / cosmetic. Light, surface-level wear that's often acceptable as normal use. Examples: a faint scuff that buffs out, a tiny stone chip, light swirl marks. Usually no repair needed.
K2 — Light. Visible but small damage at the cosmetic end. Examples: a small shallow scratch through the clear coat, a minor ding with no paint break. May or may not be chargeable depending on policy.
K3 — Moderate. Clearly visible damage that typically needs attention. Examples: a dent on a panel, a scratch down to primer, a cracked trim piece. Generally repairable and commonly chargeable.
K4 — Significant. Substantial damage affecting a panel or component. Examples: a deep dent with creasing, a cracked bumper, damaged glass. Requires repair or replacement.
K5 — Severe. Major structural or functional damage. Examples: a crushed panel, a shattered windshield, a missing or destroyed component. Significant repair, and a clear, high-severity charge.

The progression is intuitive — bigger number, worse damage — but the value is that "bigger number" is defined, not guessed. A K3 from one assessment is comparable to a K3 from another.

How AI applies a consistent grade

Manual grading still drifts. Even with a defined scale, a tired inspector at the end of a shift grades differently than a fresh one at the start, and two people will disagree on whether a given dent is a K2 or a K3. That inconsistency is exactly what undermines a report when it's challenged.

An AI inspection model is trained on graded damage examples, so it maps a photo to a severity level the same way every time — no shift drift, no inspector-to-inspector disagreement. In practice, VerifyAI returns the grade as a structured field alongside the pass/fail criteria:

The model detects damage against the policy criteria (no body damage, no broken glass, no missing parts).
It assigns a severity grade on the AIAG / K1–K5 scale.
The grade comes back in the response, so every vehicle is assessed against the same standard automatically.

For the implementation detail, see the AIAG and K-grades guide, and for how grading fits the full inspection, the vehicle damage inspection use case. The methodology behind how VerifyAI assigns grades is on the methodology page. If you want quick definitions, the glossary covers the AIAG damage grade and the K1–K5 scale.

Why the grade matters in a dispute

A grade is only useful if it changes outcomes — and it does, in two ways:

Consistency across the fleet. Every vehicle graded the same way means you can audit, compare, and trust your own data. A pattern of K4s at one location is a signal you can actually act on.
Defensibility in a chargeback. A consistent severity grade, paired with a before/after delta that isolates new damage from pre-existing wear, turns a subjective argument into a documented classification. "It's a K3 that wasn't there at pickup" is far stronger than "it looks damaged to us."

On compliance claims

VerifyAI is GDPR-aligned, with a SOC 2 audit in progress — not yet SOC 2 certified. See security and GDPR for the current status.

See grading on a real photo

The fastest way to understand the scale is to grade a real photo and read the result.

Start free in the sandbox — $5 in credit, no card required. Upload a damage photo and see the structured grade come back. To wire it into your own pipeline, see the damage inspection API quickstart, and for a survey of inspection tools, the best vehicle damage detection software roundup.

A standardized grade is a small thing that fixes a big problem: it makes every condition assessment mean the same thing — to your team, to your data, and to a card issuer reviewing a dispute.