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

Start here. Every send needs an approved template and a template_id, so this section explains both — the other sections build on it.

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=YOUR_TEMPLATE_ID&message={"name":"Aslam","otp":"1234"}

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=8584&mobile=923001234567&template_id=YOUR_TEMPLATE_ID&message={"name":"Aslam","otp":"1234"}

Response Example

curl -G 'https://sendpk.com/api/sms.php' \
  -d 'api_key=3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d' \
  -d 'sender=8584' \
  -d 'mobile=923001234567' \
  -d 'template_id=YOUR_TEMPLATE_ID' \
  -d 'message={"name":"Aslam","otp":"1234"}'

<?php
$post = http_build_query([
    'api_key'     => '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d',
    'sender'      => '8584',
    'mobile'      => '923001234567',
    'template_id' => 'YOUR_TEMPLATE_ID',
    ///only the values that change — the message text is fixed in your template
    'message'     => json_encode(['name' => 'Aslam', 'otp' => '1234']),
]);

$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: '8584',
  mobile: '923001234567',
  template_id: 'YOUR_TEMPLATE_ID',
  // only the values that change — the message text is fixed in your template
  message: JSON.stringify({ name: 'Aslam', otp: '1234' }),
});

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 json, requests

response = requests.get('https://sendpk.com/api/sms.php', params={
    'api_key': '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d',
    'sender': '8584',
    'mobile': '923001234567',
    'template_id': 'YOUR_TEMPLATE_ID',
    # only the values that change — the message text is fixed in your template
    'message': json.dumps({'name': 'Aslam', 'otp': '1234'}),
})

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&template_id=YOUR_TEMPLATE_ID&message={"name":"Aslam","amount":"2500","date":"15 Sep"}

Response Example

curl -G 'https://sendpk.com/api/sms.php' \
  -d 'api_key=3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d' \
  -d 'sender=YourBrand' \
  -d 'mobile=923001234567,923101234567' \
  -d 'template_id=YOUR_TEMPLATE_ID' \
  -d 'message={"name":"Aslam","amount":"2500","date":"15 Sep"}'

<?php
$post = http_build_query([
    'api_key'     => '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d',
    'sender'      => 'YourBrand',
    'mobile'      => '923001234567,923101234567',
    'template_id' => 'YOUR_TEMPLATE_ID',
    ///only the values that change — the message text is fixed in your template
    'message'     => json_encode(['name' => 'Aslam', 'amount' => '2500', 'date' => '15 Sep']),
]);

$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',
  template_id: 'YOUR_TEMPLATE_ID',
  // only the values that change — the message text is fixed in your template
  message: JSON.stringify({ name: 'Aslam', amount: '2500', date: '15 Sep' }),
});

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

import json, requests

response = requests.get('https://sendpk.com/api/sms.php', params={
    'api_key': '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d',
    'sender': 'YourBrand',
    'mobile': '923001234567,923101234567',
    'template_id': 'YOUR_TEMPLATE_ID',
    # only the values that change — the message text is fixed in your template
    'message': json.dumps({'name': 'Aslam', 'amount': '2500', 'date': '15 Sep'}),
})

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&template_id=YOUR_TEMPLATE_ID&message=%7B%22name%22%3A%22%D8%A7%D8%B3%D9%84%D9%85%22%2C%22order_id%22%3A%224471%22%7D&type=unicode

URL-encode the message parameter (as shown above) whenever it contains Unicode characters. Before encoding, that example reads {"name":"اسلم","order_id":"4471"}.

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. Your template's variable values go in message as JSON, each one pointing at a column 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&template_id=YOUR_TEMPLATE_ID&message={"name":"#B#","marks":"#C#","subject":"#D#"}

Sample Output

Your approved template is Your son #name# got #marks# marks in #subject#. If column B holds a name, C a score and D a subject, each recipient gets their own filled-in copy:

Your son Ali Ahmad got 1123 marks in Mathematics

Your son Mustafa Kamal got 330 marks in Mathematics

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.

List My Templates

Returns every approved Fixed-SMS template on your account, each with the template_id you pass when sending. Use it so you never have to copy an ID out of the dashboard by hand — fetch your templates once at startup, then send against the ID you got back.

Required Parameters

Request Example

GET https://sendpk.com/apps/fetch_all_fixed_templates.php?api_key=3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d

Response Example

{
  "success": "true",
  "results": [
    {
      "id": "482",
      "name": "OTP Login",
      "message": "Hello #name#, your OTP code is #otp#",
      "variables": ["name", "otp"]
    },
    {
      "id": "509",
      "name": "Order Delivered",
      "message": "Dear #username#, your order was delivered by #ridername#",
      "variables": ["username", "ridername"]
    }
  ]
}

Putting it together

Take the first template above and send it. id becomes template_id, and variables becomes your message keys:

GET https://sendpk.com/api/sms.php?api_key=3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d&sender=8584&mobile=923001234567&template_id=482&message={"name":"Aslam","otp":"1234"}

curl -G 'https://sendpk.com/apps/fetch_all_fixed_templates.php' \
  -d 'api_key=3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d'

<?php
$json = file_get_contents('https://sendpk.com/apps/fetch_all_fixed_templates.php?' . http_build_query([
    'api_key' => '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d',
]));

$data = json_decode($json, true);

if (($data['success'] ?? '') !== 'true') {
    exit('Error: ' . $data['results'][0]['error']);
}

foreach ($data['results'] as $tpl) {
    echo $tpl['id'] . ' — ' . $tpl['name'] . ' — needs: ' . implode(', ', $tpl['variables']) . "\n";
}

const params = new URLSearchParams({ api_key: '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d' });
const res = await fetch('https://sendpk.com/apps/fetch_all_fixed_templates.php?' + params);
const data = await res.json();

if (data.success !== 'true') {
  throw new Error(data.results[0].error);
}

for (const tpl of data.results) {
  console.log(tpl.id, tpl.name, 'needs:', tpl.variables.join(', '));
}

import requests

response = requests.get('https://sendpk.com/apps/fetch_all_fixed_templates.php', params={
    'api_key': '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d',
})
data = response.json()

if data.get('success') != 'true':
    raise SystemExit('Error: ' + data['results'][0]['error'])

for tpl in data['results']:
    print(tpl['id'], tpl['name'], 'needs:', ', '.join(tpl['variables']))

When there is nothing to return

{"success":"false","results":[{"status":"1","error":"No Record Found"}]}

Nothing listed yet? Submit one on the Fixed-SMS Templates page and it appears here once approved. If your account has an IP whitelist, it does not apply here: you can read your templates from your development machine, and still keep sending locked to your server's address. This endpoint also accepts the older username/password pair for existing integrations, but api_key is the way to go — it never puts your account password in a URL.

Code Examples

A reusable helper function you can paste directly into your project to start sending SMS in one line. It uses the current Fixed / OTP SMS method: your message text stays fixed in your approved template, and you pass only the values that change.

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

# template: Hello #name#, your OTP code is #otp#
send_sms "923001234567" '{"name":"Aslam","otp":"1234"}'

<?php
///$vars holds only the values that change — the wording lives in your template
function sendSms(string $mobile, array $vars): string {
    static $apiKey     = '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d';
    static $sender     = 'YourBrand';
    static $templateId = 'YOUR_TEMPLATE_ID';
    static $url        = 'https://sendpk.com/api/sms.php';

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

///template: Hello #name#, your OTP code is #otp#
$result = sendSms('923001234567', ['name' => 'Aslam', 'otp' => '1234']);
echo strpos($result, 'OK') === 0 ? 'Sent! ' . $result : 'Error: ' . $result;

// vars holds only the values that change — the wording lives in your template
async function sendSms(mobile, vars) {
  const API_KEY = '3f9a2b7c6e1d4c2a9b0e8d5f1a2b3c4d';
  const params = new URLSearchParams({
    api_key: API_KEY,
    sender: 'YourBrand',
    mobile,
    template_id: 'YOUR_TEMPLATE_ID',
    message: JSON.stringify(vars),
  });
  const res = await fetch('https://sendpk.com/api/sms.php?' + params);
  return res.text();
}

// template: Hello #name#, your OTP code is #otp#
const result = await sendSms('923001234567', { name: 'Aslam', otp: '1234' });
console.log(result);

import json, requests

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

# vars holds only the values that change — the wording lives in your template
def send_sms(mobile: str, vars: dict) -> str:
    response = requests.get(API_URL, params={
        'api_key': API_KEY,
        'sender': SENDER,
        'mobile': mobile,
        'template_id': TEMPLATE_ID,
        'message': json.dumps(vars),
    })
    return response.text

# template: Hello #name#, your OTP code is #otp#
result = send_sms('923001234567', {'name': 'Aslam', 'otp': '1234'})
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