Bulk SMS API Documentation

Send Single, Bulk, Unicode, Dynamic (mail-merge) and OTP SMS directly from your website or software over a plain HTTP request — no SDK and no OAuth handshake required. This is the exact same API that powers our own web portal, fully compatible with PHP, ASP, .NET, JSP, C# and Java integrations. Prefer to explore it visually first? Browse our full Postman collection — every endpoint on this page is pre-built there, ready to run with your own credentials.

Getting Started

From signup to your first delivered SMS in a few minutes.

Authentication

Every request is authenticated with a single api_key parameter. The older username / password login-pair auth is deprecated — use api_key on every call shown on this page.

Sender ID (Masking)

The sender parameter is the name recipients see as the message sender. It must match a Sender ID that's been approved for your account.

Base URL & Endpoints

There's one endpoint per operation — sending, dynamic/mail-merge sending, checking a delivery report, and checking your balance.

Request Parameters

Our docs are friendly enough that you don't need deep developer knowledge to integrate — here's every parameter the sms.php endpoint accepts.

The Dynamic / Personalized SMS endpoint accepts its own url and duplicate parameters instead of mobile — see its dedicated section below.

Response Format

By default the API replies with a short plain-text line. Add format=json or format=xml on any request to get the same status/ID pair back as structured data instead.

OK  Successful response

The number after ID: is your unique message ID — save it if you plan to check the delivery report later.

Status Codes

Every response starts with OK on success, or a numeric code that tells you exactly what went wrong.

Overview

One core endpoint, several ways to use it — plus a dedicated endpoint for file-based mail-merge sending. Pick the flavor that matches what you're sending.

Fixed / OTP SMS

Per PTA guidelines, SMS falls into two categories: transactional (critical/informational messages and OTPs) and promotional (marketing content). Fixed-SMS templates keep your transactional content pre-approved and PTA-compliant — only the variable parts change per message. Variables are written as #variable_name# in the approved template; you fill them in with a JSON object of matching keys.

Video Tutorial

Prefer to watch it in action? This walkthrough covers Fixed / OTP SMS end-to-end.

Creating a template

Required Parameters

Request Example

GET https://sendpk.com/api/sms.php?api_key=3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d&sender=8584&mobile=923001234567&template_id=APPROVED_ID&message={"name":"Umair","pin":"456723"}

Short Code / OTP templates typically send from a shared short code (e.g. 8584) rather than a custom brand name. Read the full walkthrough in our Fixed-SMS Templates guide.

Send Single SMS

Sends one message to one recipient.

Request Example

GET https://sendpk.com/api/sms.php?api_key=3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d&sender=YourBrand&mobile=923001234567&message=Your table is ready, see you soon!

Response Example

curl -G 'https://sendpk.com/api/sms.php' \
  -d 'api_key=3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d' \
  -d 'sender=YourBrand' \
  -d 'mobile=923001234567' \
  -d 'message=Your table is ready, see you soon!'

<?php
$post = http_build_query([
    'api_key' => '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d',
    'sender'  => 'YourBrand',
    'mobile'  => '923001234567',
    'message' => 'Your table is ready, see you soon!',
]);

$result = file_get_contents('https://sendpk.com/api/sms.php?' . $post);

if (strpos($result, 'OK') === 0) {
    echo 'Sent! ' . $result;
} else {
    echo 'Error code: ' . $result;
}

const params = new URLSearchParams({
  api_key: '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d',
  sender: 'YourBrand',
  mobile: '923001234567',
  message: 'Your table is ready, see you soon!',
});

const res = await fetch('https://sendpk.com/api/sms.php?' + params);
const text = await res.text();
console.log(text); // e.g. "OK ID:29346"

import requests

response = requests.get('https://sendpk.com/api/sms.php', params={
    'api_key': '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d',
    'sender': 'YourBrand',
    'mobile': '923001234567',
    'message': 'Your table is ready, see you soon!',
})

print(response.text)  # e.g. "OK ID:29346"

Send Bulk SMS

Sends the same message to multiple recipients in a single call. Separate numbers with a comma — duplicates and invalid numbers are filtered automatically.

Request Example

GET https://sendpk.com/api/sms.php?api_key=3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d&sender=YourBrand&mobile=923001234567,923101234567&message=Flash Sale! 30% off everything today only.

Response Example

curl -G 'https://sendpk.com/api/sms.php' \
  -d 'api_key=3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d' \
  -d 'sender=YourBrand' \
  -d 'mobile=923001234567,923101234567' \
  -d 'message=Flash Sale! 30% off everything today only.'

<?php
$post = http_build_query([
    'api_key' => '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d',
    'sender'  => 'YourBrand',
    'mobile'  => '923001234567,923101234567',
    'message' => 'Flash Sale! 30% off everything today only.',
]);

$result = file_get_contents('https://sendpk.com/api/sms.php?' . $post);
echo $result;

const params = new URLSearchParams({
  api_key: '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d',
  sender: 'YourBrand',
  mobile: '923001234567,923101234567',
  message: 'Flash Sale! 30% off everything today only.',
});

const res = await fetch('https://sendpk.com/api/sms.php?' + params);
console.log(await res.text());

import requests

response = requests.get('https://sendpk.com/api/sms.php', params={
    'api_key': '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d',
    'sender': 'YourBrand',
    'mobile': '923001234567,923101234567',
    'message': 'Flash Sale! 30% off everything today only.',
})

print(response.text)

Send Unicode SMS

Set type=unicode to send emoji, Urdu, or any other non-Latin script text. Unicode messages have a shorter per-part character limit than plain text, exactly as with any standard SMS.

Request Example

GET https://sendpk.com/api/sms.php?api_key=3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d&sender=YourBrand&mobile=923001234567&message=%D8%A2%D9%BE%DA%A9%D8%A7+%D8%A2%D8%B1%D8%AF%D8%B1+%D9%85%D9%84+%DA%AF%DB%8C%D8%A7&type=unicode

URL-encode the message parameter (as shown above) whenever it contains Unicode characters.

Dynamic / Personalized SMS

Send bulk SMS with unique information for every contact in a file (.txt, .csv, .xls or .xlsx) — no need to loop single sends. Reference each column in your message with #B#, #C#, #D# (matching the spreadsheet's column letters), and every recipient gets their own row's values filled in automatically.

Required Parameters

Optional Parameters

Request Example

GET https://sendpk.com/api/personalised.php?api_key=3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d&sender=YourBrand&url=https://yourdomain.com/contacts.xlsx&message=Your Son #B# Got #C# Marks In #D#, Your Son Result Is #E#. Please contact the school principal for more details.

Sample Output

If column B holds a name, C a score, D a subject and E a result, each recipient gets their own filled-in copy:

Your Son Ali Ahmad Got 1123 Marks In Mathematics, Your Son Result Is Pass. Please contact the school principal for more details.

Your Son Mustafa Kamal Got 330 Marks In Mathematics, Your Son Result Is Fail. Please contact the school principal for more details.

This is the same mail-merge feature behind the "Send Dynamic Message" request in our Postman collection.

Check Balance

Checks your remaining SMS credit through a simple HTTP call — handy for showing a live balance inside your own app or dashboard.

Request Example

GET https://sendpk.com/api/balance.php?api_key=3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d

Returns your remaining SMS credit as a plain number, or the matching status code if the request fails.

Delivery Report

Looks up the current delivery status of a previously sent message using the message ID returned by the send API.

Request Example

GET https://sendpk.com/api/delivery.php?api_key=3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d&id=29346

Pass the message id from the OK ID: response you received when the message was sent.

Code Examples

A reusable helper function you can paste directly into your project to start sending SMS in one line.

# Reusable shell function
send_sms() {
  curl -s -G 'https://sendpk.com/api/sms.php' \
    -d "api_key=$SENDPK_API_KEY" \
    -d "sender=$SENDPK_SENDER" \
    -d "mobile=$1" \
    -d "message=$2"
}

send_sms "923001234567" "Hello from cURL!"

<?php
function sendSms(string $mobile, string $message): string {
    static $apiKey = '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d';
    static $sender = 'YourBrand';
    static $url    = 'https://sendpk.com/api/sms.php';

    return file_get_contents($url . '?' . http_build_query([
        'api_key' => $apiKey,
        'sender'  => $sender,
        'mobile'  => $mobile,
        'message' => $message,
    ]));
}

$result = sendSms('923001234567', 'Hello from PHP!');
echo strpos($result, 'OK') === 0 ? 'Sent! ' . $result : 'Error: ' . $result;

async function sendSms(mobile, message) {
  const API_KEY = '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d';
  const params = new URLSearchParams({
    api_key: API_KEY,
    sender: 'YourBrand',
    mobile,
    message,
  });
  const res = await fetch('https://sendpk.com/api/sms.php?' + params);
  return res.text();
}

const result = await sendSms('923001234567', 'Hello from JavaScript!');
console.log(result);

import requests

API_KEY = '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d'
SENDER = 'YourBrand'
API_URL = 'https://sendpk.com/api/sms.php'

def send_sms(mobile: str, message: str) -> str:
    response = requests.get(API_URL, params={
        'api_key': API_KEY,
        'sender': SENDER,
        'mobile': mobile,
        'message': message,
    })
    return response.text

result = send_sms('923001234567', 'Hello from Python!')
print(result)

Postman & Downloads

Prefer exploring the API outside your code editor first? Grab our Postman collection or the full offline documentation bundle.

Frequently Asked Questions

Support