I-CAR Standards Every Body Shop Should Know for Supplement Letters

Why I-CAR Standards Matter in Supplement Letters

I-CAR (Inter-Industry Conference on Auto Collision Repair) is the industry's primary training and standards organization. Its standards are developed collaboratively by insurers, OEMs, and repair professionals — which means they carry weight with all parties in a supplement dispute. When you cite an I-CAR standard in a supplement letter, you're citing a document that the insurance company's own industry representatives helped create.

I-CAR standards are also widely referenced in state insurance regulations and court decisions, which gives them legal authority beyond their industry standing.

Key I-CAR Standards for Supplement Letters

I-CAR REF-01: Structural Replacement

This is the most commonly cited I-CAR standard in supplement letters. REF-01 defines the conditions under which structural components must be replaced rather than repaired. The key threshold is 12mm of deformation — components deformed beyond this threshold must be replaced, not straightened. When your supplement involves structural replacement, cite REF-01 and include the measurement that exceeds the threshold.

I-CAR WCA-01: Welding

WCA-01 covers welding procedures for collision repair, including the requirement for weld-through primer and the prohibition on certain welding techniques on high-strength steel. When your supplement involves welding operations or corrosion protection at weld joints, WCA-01 provides the citation.

I-CAR HSS-01: High-Strength Steel

HSS-01 covers the repair of high-strength steel (HSS) and ultra-high-strength steel (UHSS) components. Modern vehicles use extensive amounts of HSS and UHSS in their structural systems, and these materials require specialized repair procedures. When your supplement involves structural repairs to modern vehicles, HSS-01 is often relevant.

I-CAR ADV-01: Advanced Materials

ADV-01 covers the repair of advanced materials including aluminum, carbon fiber, and other composites increasingly used in modern vehicles. When your supplement involves repairs to aluminum panels or structural components, ADV-01 provides the citation.

I-CAR SPS-01: Squeeze-Type Resistance Spot Welding

SPS-01 covers the use of squeeze-type resistance spot welding (STRSW) in collision repair. Many OEMs require STRSW for structural repairs, and this standard defines the equipment and procedure requirements. When your supplement includes STRSW operations, SPS-01 is the relevant citation.

How to Cite I-CAR Standards

When citing I-CAR standards in a supplement letter, use the format: "I-CAR [Standard Number], [Standard Title], [Relevant Section]." For example: "I-CAR REF-01, Structural Replacement, Section 3.2 — Components exhibiting deformation exceeding 12mm must be replaced, not repaired. The left rear quarter panel inner structure exhibits 14.2mm of deformation as measured during teardown."

You can access I-CAR standards through the I-CAR website (i-car.com) or through your estimating platform's reference library.