Decode State ID Card PDF417 Barcodes with C# / .NET

ID Cards Use the Same Barcode, but Not the Same Fields

People who do not drive carry a state or provincial identification card instead of a driver license. The back of most of these cards carries the same AAMVA PDF417 barcode as a license, so a check-in, age-verification, or onboarding flow will receive both. The difference is inside the record: an ID card has no license class, restrictions, or endorsements, and treating it as a license with missing fields leads to confusing validation errors.

One C# / .NET Request for Licenses and ID Cards

Send the card back to the PDF417 API. StructOCR decodes the barcode, parses the record defined by the AAMVA DL/ID standard, and returns document_kind as id_card or driver_license. Test a sample first in the free PDF417 scanner.

Where ID Card Barcodes Show Up

• Age and identity checks: Accept non-drivers at alcohol, cannabis, and venue check-in without a separate ID card flow.
• Account onboarding: Pre-fill name, date of birth, and address from either card type and label the document correctly in your records.
• License-only workflows: Use document_kind to stop rental or fleet sign-ups that require a driver license when an ID card is presented.

Implementation: C# / .NET REST Request

Base64 encode the card-back image, send it with the x-api-key header, branch on document_kind, and treat HTTP 422 as a request for a clearer image.

Prerequisite: .NET 8+ with `System.Net.Http.Json`

using System.Net.Http.Json;
using System.Text.Json;

using var http = new HttpClient { Timeout = TimeSpan.FromSeconds(30) };
http.DefaultRequestHeaders.Add("x-api-key", Environment.GetEnvironmentVariable("STRUCTOCR_API_KEY"));

var image = await File.ReadAllBytesAsync("id-card-back.jpg");
var payload = new { img = Convert.ToBase64String(image) };
using var response = await http.PostAsJsonAsync("https://api.structocr.com/v1/driver-license-pdf417", payload);
var body = await response.Content.ReadAsStringAsync();

using var result = JsonDocument.Parse(body);
if ((int)response.StatusCode == 422)
{
    Console.WriteLine("Retake image: " + result.RootElement.GetProperty("error").GetString());
}
else
{
    response.EnsureSuccessStatusCode();
    var data = result.RootElement.GetProperty("data");
    var idCard = data.GetProperty("document_kind").GetString() == "id_card";
    Console.WriteLine((idCard ? "State/provincial ID: " : "Driver license: ")
        + data.GetProperty("document_number").GetString());
    Console.WriteLine("DOB: " + data.GetProperty("date_of_birth").GetString());
}

Sample ID Card JSON Output

The example uses fictional values. License-only elements such as vehicle_class are null for ID cards; type stays drivers_license for compatibility.

{
  "success": true,
  "data": {
    "type": "drivers_license",
    "document_kind": "id_card",
    "source": "pdf417",
    "country_code": "USA",
    "region": "NY",
    "document_number": "SAMPLEID123",
    "surname": "SAMPLE",
    "given_names": "ALEX MORGAN",
    "first_name": "ALEX",
    "middle_name": "MORGAN",
    "name_suffix": null,
    "sex": "F",
    "date_of_birth": "1990-01-15",
    "date_of_issue": "2025-01-15",
    "date_of_expiry": "2033-01-15",
    "address": "100 EXAMPLE AVE",
    "city": "SAMPLE CITY",
    "postal_code": "10001",
    "vehicle_class": null,
    "restrictions": null,
    "endorsements": null,
    "height": null,
    "eye_color": null,
    "document_discriminator": "SAMPLE-DISCRIMINATOR",
    "issuer_identification_number": "636000",
    "aamva_version": 10,
    "jurisdiction_version": 0
  }
}