Reading Pre-1981 Classic Car VINs and Serial Numbers

Where to Find the VIN on a Classic Car (Pre-1981)

The standardized 17-character VIN started with model year 1981. Older vehicles use manufacturer-specific serial numbers of varying length, often on a dash or door-pillar plate.

Capture and Extract It Reliably

Treat short or irregular serials as valid historical identifiers and do not force 17-character validation on them. Then send the photo to the VIN OCR API, which returns the VIN and the surface it was read from. Test with the free VIN scanner.

Where This Fits

• Classic car insurance: Replace manual transcription of 17-character identifiers with a photo.
• Auction and appraisal intake: Attach the extracted VIN and its source surface to the record for audit.
• Restoration records: Send low-confidence reads to a review queue instead of saving them.

Python Example

Send the image as Base64 JSON and read the VIN fields.

Prerequisite: Python 3.9+, `pip install requests`, and a STRUCTOCR_API_KEY

import base64
import os
import requests

with open("vin.jpg", "rb") as image_file:
    image = base64.b64encode(image_file.read()).decode("ascii")

response = requests.post(
    "https://api.structocr.com/v1/vin",
    headers={"x-api-key": os.environ["STRUCTOCR_API_KEY"]},
    json={"img": image},
    timeout=30,
)
response.raise_for_status()
data = response.json()["data"]
print("vin:", data.get("vin"))
print("confidence:", data.get("confidence"))
print("carrier_type:", data.get("carrier_type"))

Sample VIN Response

Illustrative response using the Wikipedia sample VIN. The API returns the VIN as read; decoding happens in a separate step.

{
  "success": true,
  "data": {
    "vin": "1M8GDM9AXKP042788",
    "confidence": "High",
    "carrier_type": "metal_plate"
  }
}