Free Auto Body Supplement Letter Template (And Why AI Does It Better)

The Case for Templates

If you're writing supplement letters from scratch every time, a template is a significant improvement. A well-designed template ensures you include all the required information (claim number, vehicle details, damage description, OEM citations, line-item breakdown) and presents it in a professional format that adjusters recognize and respond to.

Here's a basic supplement letter template you can use as a starting point:

[SHOP NAME]
[SHOP ADDRESS]
[SHOP PHONE] | [SHOP EMAIL]
[DATE]

[ADJUSTER NAME]
[INSURANCE COMPANY]
[ADJUSTER EMAIL]

RE: Supplement Request — Claim #[CLAIM NUMBER]
    [VEHICLE YEAR MAKE MODEL] | VIN: [VIN]
    Supplement Amount: $[AMOUNT]

Dear [ADJUSTER NAME],

Upon teardown of the above-referenced vehicle, our certified technicians 
discovered additional damage not visible during the initial inspection. 
This letter formally requests a supplement to the original approved estimate.

ADDITIONAL DAMAGE FOUND:

1. [PART NAME] — [REPAIR/REPLACE]
   [Technical description of damage including measurements]
   Justification: [OEM procedure citation or I-CAR standard]

2. [PART NAME] — [REPAIR/REPLACE]
   [Technical description of damage including measurements]
   Justification: [OEM procedure citation or I-CAR standard]

SUPPLEMENT LINE ITEMS:
[Operation] — [Hours] hrs @ $[Rate]/hr = $[Total]
[Part Name] — OEM Part #[Part Number] = $[Cost]
[Operation] — [Hours] hrs @ $[Rate]/hr = $[Total]

SUPPLEMENT TOTAL: $[TOTAL]

Supporting documentation including photographs of the additional damage 
is attached. We respectfully request approval within [X] business days 
to avoid delaying the vehicle owner's repair.

Sincerely,
[YOUR NAME]
[SHOP NAME]

The Limitations of Templates

Templates have a fundamental limitation: they're generic. A template can give you the structure, but it can't give you the right OEM citation for a 2022 Toyota Camry vs. a 2021 Honda Accord. It can't look up the specific I-CAR standard that applies to the type of damage you found. And it can't write the damage description in the technical language that adjusters respond to.

Every supplement letter needs to be customized for the specific vehicle, the specific damage, and the specific insurance company. A template that isn't customized is only marginally better than no template at all.

Why AI-Generated Supplement Letters Get Approved at Higher Rates

Supplement Tool generates supplement letters that are customized for your specific claim — not just filled-in templates. The AI knows the OEM repair procedures for your specific vehicle, the I-CAR standards that apply to the type of damage you found, and the language that adjusters at each insurance company respond to. The result is a letter that reads like it was written by an experienced estimator who knows exactly what they're doing.

Shops using Supplement Tool report approval rates 15–25% higher than their previous approach. The difference isn't the format — it's the specificity and authority of the language.