Thai National ID Card OCR

1.25 ICper page (front) · 0.75 IC (back)

v3.6.0-20260824 Active Since Nov 2019 Updated 24 Aug 2026 5,000 cards/hour 98.0% accuracy Whitepaper (PDF) POST /v3/store/ekyc/thai-national-id-card

Mobile & Web SDK available

Skip the camera work — our free open-source eKYC SDK (Web, Flutter, iOS, Android & React Native) auto-captures documents and faces and calls this API for you. View on GitHub.

The Thai National ID Card OCR API extracts structured data from both faces of the Thai national ID card: the 13-digit ID number, names in Thai and English, address, dates, religion, and gender from the front, and the laser code from the back — with per-field confidence scores and optional bounding boxes, cropped images, and raw values. The production service processes a card in 1.4 seconds (median) and sustains 5,000 cards per hour. Measured field-level accuracy is 98.0 percent against human-verified ground truth, with the ID number at 100 percent; see Accuracy.

Live Demo

Upload a Thai national ID card, or use the synthetic specimens below.

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Example Images (Click to try)

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API Key

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Choose Endpoint URL

Endpoint URL

cURL Command

Upload Image

Try the SDK (Live Camera)

Prefer not to upload a file? The free open-source iApp eKYC Web SDK captures the card automatically from your camera — it detects the card boundary, waits for a sharp stable frame, perspective-corrects the image, and submits it to this API. See more flows on the full SDK live demo page.

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Quick Start

You need an API key from the API Key Management page. Send the image as multipart/form-data:

curl -X POST https://api.iapp.co.th/v3/store/ekyc/thai-national-id-card/front \
  -H "apikey: YOUR_API_KEY" \
  -F "file=@idcard.jpg"

{
    "id_number": "3411700830334",
    "th_name": "นาง บุญยัง โลเปช",
    "en_name": "Mrs. Bunyang Lopez",
    "en_dob": "22 Mar. 1957",
    "address": "33/349 หมู่ที่ 7 ต.หนองปรือ อ.บางละมุง จ.ชลบุรี",
    "province": "ชลบุรี",
    "detection_score": 0.979
}

The full response schemas, processing options, and error codes are in the Technical Reference.

Endpoints and Pricing

Endpoint	Output	Price
POST /v3/store/ekyc/thai-national-id-card/front	JSON with all front-side fields, per-field confidence, and optional bounding boxes and images	1.25 IC per page
POST /v3/store/ekyc/thai-national-id-card/back	JSON with the back-side laser code	0.75 IC per page

The legacy paths /thai-national-id-card/v3.5/front and /thai-national-id-card/v3.5.1/back remain supported at the same prices. For photographed photocopies, use Photographed Thai National ID Card With Signature Detection. For on-premise deployment, see Data Security.

Performance

Measured on the production service, August 2026.

Metric	Value
Median processing time	1.4 s per card (front); 1.3 s (back)
Sustained throughput	1.4 cards per second (5,000 cards per hour)
Maximum file size	10 MB
Supported input formats	JPEG, JPG, PNG, HEIC, HEIF, PDF

Accuracy

Accuracy is measured against human-verified ground truth: 60 labeled Thai national ID cards, 1,380 individual field observations. The ground-truth dataset contains real ID cards and is kept private for privacy reasons; the methodology is fully specified in the whitepaper below.

Field	Exact match
ID number (13 digits)	100%
Surname (English), name titles, gender, religion	100%
Sub-district, district, postal code	100%
Province, dates of birth and expiry	100%
Address (full)	98.3%
Full name (Thai)	93.3%
All fields (overall)	98.0%

The recognition engine was upgraded in August 2026, raising overall field accuracy from 97.8% to 98.0%, with the largest gains on addresses, province, and expiry dates. One honest caveat: Thai given/family-name fields moved slightly the other way (full Thai name 93.3%, versus 96.7% before) — if your integration keys specifically on Thai names rather than the ID number or address, validate them against the per-field confidence scores. Full methodology, per-field results, and comparison against a leading global cloud OCR service are published in the benchmark whitepaper:

Download the benchmark whitepaper (PDF)

Data Security and Compliance

• The service is GDPR and PDPA compliant.
• Uploaded images are processed in memory and are not retained after the response is returned.
• A fully self-contained on-premise deployment is available, in which no card data leaves your infrastructure. Contact us for details.

Technical Reference

Thai National ID Card Endpoints

1. Thai National ID Card - Front Side

POST /v3/store/ekyc/thai-national-id-card/front

Extracts detailed information from the front side of a Thai national ID card.

Request Headers

Name	Type	Required	Description
apikey	string	Yes	Your API key

Request Body (multipart/form-data)

Parameter	Type	Required	Description
file	File	Yes	The binary data of the image (front side)
fields	String	No	Option to choose fields in output
options	String	No	Option to choose processing tools and settings

---

2. Thai National ID Card - Back Side

POST /v3/store/ekyc/thai-national-id-card/back

Extracts information from the back side of a Thai national ID card.

Request Headers

Name	Type	Required	Description
apikey	string	Yes	Your API key

Request Body (multipart/form-data)

Parameter	Type	Required	Description
file	File	Yes	The binary data of the image (back side)
options	String	No	Option to choose processing tools and settings

Available Options

• not_crop_card - Skip card cropping
• not_rotate_card - Skip auto-rotation
• get_bbox - Return bounding box coordinates
• get_image - Return processed image
• get_original - Return original image

Response Format for Available Options

When using the available options, the response JSON will include additional fields based on the options selected:

Response with get_bbox Option

Returns bounding box coordinates for each detected field in the format [x1, y1, x2, y2] with confidence score:

{
    "bbox": {
        "address": [
            [[119, 292, 376, 334], 0.991],
            [[75, 330, 255, 362], 0.999]
        ],
        "card": [[[0, 0, 713, 462], 0.99]],
        "en_dob": [[[370, 235, 526, 266], 0.999]],
        "face": [[[544, 218, 708, 407], 0.999]]
        // Other field coordinates...
    }
}

Response with get_image Option

Returns base64 encoded cropped images for each detected field:

{
    "image": {
        "address": ["/9j/4AAQSk...", "/9j/4AAQSk..."],
        "card": ["/9j/4AAQSk..."],
        "face": ["/9j/4AAQSk..."],
        "id_number": ["/9j/4AAQSk..."]
        // Other field images...
    }
}

Response with get_original Option

Returns the original values before the autocorrect step (which occured in the post processing step) detected from the card:

{
    "original": {
        "address": "XXXXX XXXXX X ต.หนองปรือ อ.บางละมุง จ.ชลบุรี",
        "en_dob": "XX Mar. 1957",
        "en_expire": "XX Mar. 2025",
        "th_name": "นาง XXXXXX โลเปซ"
        // Other original field values...
    }
}

The response will always include the standard fields like detection_score, error_message, and process_time regardless of options used.

Responses

Front side

Request:

curl -X POST https://api.iapp.co.th/v3/store/ekyc/thai-national-id-card/front
    -H "apikey: YOUR_API_KEY"
    -F "file=@/path/to/idcard.jpg"

Response:

{
    "address": "XXXXXX XXXX X ต.หนองปรือ อ.บางละมุง จ.ชลบุรี",
    "alley": "",
    "detection_score": 0.981011797984441,
    "district": "บางละมุง",
    "en_dob": "XX Mar. 1957",
    "en_expire": "XX Mar. 2025",
    "en_fname": "XXXXXX",
    "en_init": "Mrs.",
    "en_issue": "26 Jul. 2016",
    "en_lname": "Lopez",
    "en_name": "Mrs. XXXXXX Lopez",
    "error_message": "",
    "face": "/9j/4AAQ...UAFFFFAH/9k=", # Base64 of photo's image
    "gender": "Female",
    "home_address": "XXXXX XXX",
    "house_no": "XXXXXX",
    "id_number": "34117XXXXXX334",
    "id_number_status": 1,
    "lane": "",
    "postal_code": "20150", # Automatic Retrieve from Database
    "process_time": 1.3018648624420166, # Seconds
    "province": "ชลบุรี",
    "religion": "",
    "request_id": null,
    "road": "",
    "sub_district": "หนองปรือ",
    "th_dob": "XX มี.ค. 2500",
    "th_expire": "XX มี.ค. 2568",
    "th_fname": "XXXXX",
    "th_init": "นาง",
    "th_issue": "XX ก.ค. 2559",
    "th_lname": "โลเปซ",
    "th_name": "นาง XXXXX โลเปซ",
    "village": "",
    "village_no": "7",
    "confidence": {
        "id_number": 0.95,
        "th_name": 0.95,
        "th_fname": 0.95,
        "th_lname": 0.95,
        "en_name": 0.95,
        "en_fname": 0.95,
        "en_lname": 0.95,
        "th_dob": 0.9,
        "en_dob": 0.9,
        "th_issue": 0.9,
        "en_issue": 0.9,
        "th_expire": 0.9,
        "en_expire": 0.9,
        "address": 0.95,
        "gender": 0.95,
        "religion": 0.9
    }
}

Backside

Request:

curl --location --request POST 'https://api.iapp.co.th/v3/store/ekyc/thai-national-id-card/back' \
    --header 'apikey: {Your API Key}' \
    --form 'file=@"path/to/id-card-back.jpg"'

Response:

{
    "back_number": "JT0-XXXXXXX-05",
    "detection_score": 0.99846746524175,
    "process_time": 1.370201416015625
}

Supported Fields

Front Side

Field	Type	Description
address	String	Address on the ID card
detection_score	float	Detection score of a related field
district	String	District name on the ID card
en_dob	String	Date of birth, in English
en_expire	String	Date of expiry, in English
en_fname	String	English given name
en_init	String	Name title, in English
en_issue	String	Date of issue, in Thai
en_lname	String	English surname
en_name	String	English given name and surname
error_message	String	Error message
face	String	Base64 character string converted from the image
gender	String	Gender
home_address	String	Home address on the ID card
id_number	String	National ID number
postal_code	String	Postal Code
process_time	String	Processing time (Sec.)
province	String	Province name on the ID card
religion	String	Religion on the ID card
sub_district	String	Sub district name on the ID card
th_dob	String	Date of birth, in Thai
th_expire	String	Date of expiry, in Thai
th_fname	String	Thai given name
th_init	String	Name title, in English
th_issue	String	Date of issue
th_lname	String	Thai surname
th_name	String	Thai given name and surname
confidence	Object	Confidence scores (0-1) for each extracted field

Back side

Field	Type	Description
back_number	String	Laser number on back of ID card

Common Response Fields

Field	Type	Description
detection_score	Float	Confidence score (0-1)
error_message	String	Error message if request fails
process_time	Float	Processing time in seconds

Error Code

Specific Error Messages

Thai National ID Card Front Side

Status Code	Status Message	Description
420	NO_ID_CARD_FOUND	The image file is not the ID card
421	IMAGE_ERROR_UNSUPPORTED_FORMAT	The image cannot be resolved. The file format may not be supported or the file is damaged
422	INVALID_IMAGE_SIZE	The size of the uploaded image does not meet the requirement
424	PLEASE_VERIFY_ID_CARD_NUMBER	The National ID Number has 13 digits but is incorrect. Response code 424 will show when using id_check option
425	CANNOT_READ_ID_CARD_NUMBER_CLEARLY	The National ID Number has less than 13 digits. Response code 425 will show when using id_check option
426	IMAGE_ERROR_UNSUPPORTED_BLACK_WHITE_IMAGE	Used gray_check option to check black-white and gray images

Thai National ID Card Back Side

Status Code	Status Message	Description
430	NO_ID_CARD_FOUND	The image file is not the ID Card
431	IMAGE_ERROR_UNSUPPORTED_FORMAT	The image cannot be resolved. The file format may not be supported or the file is damaged
432	INVALID_IMAGE_SIZE	The size of the uploaded image does not meet the requirement
434	LASER_NUMBER_NOT_FOUND	Cannot detect the laser number on back ID Card
435	CANNOT_READ_LASER_NUMBER_CLEARLY	The laser number has less than 12 digits. Response code 435 will show when using id_check option
436	IMAGE_ERROR_UNSUPPORTED_BLACK_WHITE_IMAGE	Used gray_check option to check black-white and gray images

Common Error Messages

Status Code	Status Message	Description
404	REQUESTED_URL_NOT_FOUND	API Route not found in request
405	METHOD_NOT_ALLOWED	Method name (GET, POST) in the URL is incorrect
413	FILE_IS_TOO_LARGE: (more than 2 MB)	The file size is too large
427	LONG_TIME_TO_PROCESS	The server is processed for a long time
428	LONG_TIME_TO_REQUEST	The client is waiting in the queue for a long time
461	NO_FILE_ATTACHED	No file attached
560	SERVER_IS_BUSY: (Please try again in a few seconds.)	Server is working on many requests
563	ID_CARD_API_NOT_SUPPORT_THIS_IMAGE	The API has an error in the process

Code Examples

cURL

curl -X POST https://api.iapp.co.th/v3/store/ekyc/thai-national-id-card/front \
  -H "apikey: YOUR_API_KEY" \
  -F "file=@idcard.jpg"

Python

import requests

url = "https://api.iapp.co.th/v3/store/ekyc/thai-national-id-card/front"
headers = {"apikey": "YOUR_API_KEY"}
files = {"file": open("idcard.jpg", "rb")}

response = requests.post(url, headers=headers, files=files)
print(response.json())

JavaScript

const axios = require("axios");
const FormData = require("form-data");
const fs = require("fs");

const data = new FormData();
data.append("file", fs.createReadStream("idcard.jpg"));

axios.post("https://api.iapp.co.th/v3/store/ekyc/thai-national-id-card/front", data, {
    headers: { apikey: "YOUR_API_KEY", ...data.getHeaders() },
})
    .then((response) => console.log(response.data))
    .catch((error) => console.log(error));

PHP

<?php
$curl = curl_init();

curl_setopt_array($curl, array(
    CURLOPT_URL => 'https://api.iapp.co.th/v3/store/ekyc/thai-national-id-card/front',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => array(
        'file' => new CURLFILE('idcard.jpg')
    ),
    CURLOPT_HTTPHEADER => array(
        'apikey: YOUR_API_KEY'
    ),
));

$response = curl_exec($curl);
curl_close($curl);
echo $response;
?>

Swift

import Foundation

let url = URL(string: "https://api.iapp.co.th/v3/store/ekyc/thai-national-id-card/front")!
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.addValue("YOUR_API_KEY", forHTTPHeaderField: "apikey")

let boundary = "Boundary-\(UUID().uuidString)"
request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")

var body = Data()
body.append("--\(boundary)\r\n".data(using: .utf8)!)
body.append("Content-Disposition: form-data; name=\"file\"; filename=\"idcard.jpg\"\r\n".data(using: .utf8)!)
body.append("Content-Type: image/jpeg\r\n\r\n".data(using: .utf8)!)
if let fileData = try? Data(contentsOf: URL(fileURLWithPath: "idcard.jpg")) {
    body.append(fileData)
}
body.append("\r\n--\(boundary)--\r\n".data(using: .utf8)!)
request.httpBody = body

URLSession.shared.dataTask(with: request) { data, response, error in
    if let data = data {
        print(String(data: data, encoding: .utf8)!)
    }
}.resume()

Kotlin

import okhttp3.*
import okhttp3.MediaType.Companion.toMediaTypeOrNull
import okhttp3.RequestBody.Companion.asRequestBody
import java.io.File

val client = OkHttpClient()
val file = File("idcard.jpg")

val requestBody = MultipartBody.Builder()
    .setType(MultipartBody.FORM)
    .addFormDataPart("file", file.name, file.asRequestBody("image/jpeg".toMediaTypeOrNull()))
    .build()

val request = Request.Builder()
    .url("https://api.iapp.co.th/v3/store/ekyc/thai-national-id-card/front")
    .addHeader("apikey", "YOUR_API_KEY")
    .post(requestBody)
    .build()

client.newCall(request).execute().use { response ->
    println(response.body?.string())
}

Java

import okhttp3.*;
import java.io.File;

OkHttpClient client = new OkHttpClient();
File file = new File("idcard.jpg");

RequestBody requestBody = new MultipartBody.Builder()
    .setType(MultipartBody.FORM)
    .addFormDataPart("file", file.getName(),
        RequestBody.create(MediaType.parse("image/jpeg"), file))
    .build();

Request request = new Request.Builder()
    .url("https://api.iapp.co.th/v3/store/ekyc/thai-national-id-card/front")
    .addHeader("apikey", "YOUR_API_KEY")
    .post(requestBody)
    .build();

try (Response response = client.newCall(request).execute()) {
    System.out.println(response.body().string());
}

Dart

import 'package:http/http.dart' as http;

var request = http.MultipartRequest(
    'POST',
    Uri.parse('https://api.iapp.co.th/v3/store/ekyc/thai-national-id-card/front'),
);
request.files.add(await http.MultipartFile.fromPath('file', 'idcard.jpg'));
request.headers.addAll({'apikey': 'YOUR_API_KEY'});

var response = await request.send();
print(await response.stream.bytesToString());

Limitations and Best Practices

Limitations

• Maximum file size: 10MB
• Supported formats: JPEG, JPG, PNG, HEIC, HEIF, PDF

Best Practices

1. Ensure good image quality
2. Check detection_score in response
3. Handle error messages appropriately
4. Validate ID card number format
5. Consider using options parameter for specific needs

Thai National ID Card Specifications

Understanding the physical specifications of Thai National ID cards helps ensure optimal image capture for OCR processing.

Card Dimensions (ขนาดบัตรประชาชน)

Specification	Metric	Imperial (inches)
Width	85.60 mm	3.370 inches (3⅜")
Height	53.98 mm	2.125 inches (2⅛")
Thickness	0.76 mm	0.030 inches
Corner Radius	3.18 mm	0.125 inches

ขนาดบัตรประชาชน นิ้ว

บัตรประชาชนไทยมีขนาด 3.370 × 2.125 นิ้ว (85.60 × 53.98 มม.) ตามมาตรฐาน ISO/IEC 7810 ID-1 ซึ่งเป็นขนาดเดียวกับบัตรเครดิตทั่วโลก

Card Format Standards

Standard	Description
Format	ISO/IEC 7810 ID-1 (Credit card size)
Material	Polycarbonate (PC) plastic
Chip Type	Contact smart card chip (since 2005)
Data Storage	Biometric data, digital certificate, fingerprint templates

Card Features

• Front Side: Photo, name (Thai/English), ID number, date of birth, address, issue/expiry dates, barcode
• Back Side: Laser code (12-character alphanumeric)
• Security Features: Hologram, UV printing, microtext, laser engraving
• Smart Card Chip: Contains encrypted biometric data and digital signature

Image Requirements for OCR

For optimal OCR accuracy, ensure your captured images meet these requirements:

Requirement	Recommended	Minimum
Resolution	600 DPI	300 DPI
Image Width	1000+ pixels	600 pixels
Image Height	630+ pixels	400 pixels
File Size	< 5 MB	< 10 MB
Format	JPEG, PNG	JPEG, PNG, HEIC, PDF

Changelog

Version	Date	Accuracy	Changes
v3.6.0-20260824	24 Aug 2026	98.0% field-level	English-format dates (en_dob, en_issue, en_expire) now match the card's printed format: abbreviated month names carry a dot (23 Apr. 1997); May, printed unabbreviated, has none. Verified on 60 cards — only these three fields changed and every Thai field is identical. Update client-side date parsing to accept the dotted form.
v3.5.3-20260824	24 Aug 2026	98.0% field-level	Upgraded recognition engine: overall field accuracy 97.8% to 98.0% against human-verified ground truth, ID number at 100%; largest gains on addresses, province, and expiry dates. Median processing 1.4 s per card. Fully self-contained on-premise deployment available.
3.5	Nov 2022	98.13% character-level	New OCR engine, faster processing.
3.4	Jul 2022	93.25%	Added Thai military ranks.
3.0	Feb 2021	91.75%	Major accuracy improvements.
2.0	Feb 2020	85%	Added back-side support.
1.0	Nov 2019	76%	Initial release.