App integration.

SMS built into your mobile and web applications

Your app needs instant, reliable reach — whether it's delivering a verification code in under 3 seconds, sending a transaction alert, or falling back to SMS when push notifications fail. Our API integrates directly into your application's codebase, giving you full control over messaging with the performance your users expect.

get api key view docs
terminal — 2FA verification

Request

curl -X POST \
https://api.faretext.co.uk/v1/sms
-H "Authorization: Bearer ft_k3y..." \
-d '{
"to": "+447700900000",
"message": "Your code is 847291"
}'
sending...

Response 200 OK

{
"status": "sent",
"message_id": "msg_2fa_9x4k",
"credits_used": 1
}
cURL PHP .NET Python Java Ruby
600 msg/sec 98.5% delivery <200ms latency Multi-language SDKs

App SMS Lifecycle

SMS across your app lifecycle.

From the first sign-up to long-term retention, SMS plays a role at every stage of your user's journey.

Onboarding

  • Phone number verification
  • Welcome messages
  • Setup guidance prompts

Authentication

  • 2FA login codes
  • Password reset OTPs
  • New device verification

Transactional

  • Payment confirmations
  • Order status updates
  • Receipt delivery

Engagement

  • Feature announcements
  • In-app event alerts
  • Push notification fallback

Retention

  • Win-back campaigns
  • Subscription renewal alerts
  • Loyalty & reward updates

Two-Factor Authentication

The gold standard for identity verification.

Over 80% of businesses use SMS for two-factor authentication. It's the most widely adopted verification method because it works on every phone, doesn't require an app, and reaches users even without internet. Your verification code is delivered in under 3 seconds, with 98.5% delivery rates on direct UK network routes.

Login verification
Password resets
Account recovery
Payment confirmation
New device alerts
Suspicious activity flags

YourApp

now

Your verification code is 847291. It expires in 5 minutes. Don't share this code with anyone.

Performance

0

messages per second

peak throughput

0%

delivery rate

direct network routes

<200ms

average latency

request to delivery

0%

platform uptime

carrier-grade reliability

Push Fallback

Scenario

Push

SMS

App not installed

Notifications disabled

No internet connection

Battery saver mode

When push fails, SMS delivers.

Push notifications are convenient — when they work. But they fail silently when the app isn't installed, notifications are disabled, the phone has no internet, or battery saver mode blocks background processes. SMS bypasses all of these. It works on every phone, doesn't require an app or internet connection, and delivers to the device's native messaging inbox. For critical communications — verification codes, transaction alerts, security warnings — SMS is the guaranteed fallback that ensures your message always arrives.

sms api

Developer Tools

Multi-language support.

Our API works with every major programming language. Copy and paste working code samples, follow our documentation, and integrate SMS into your app in minutes — regardless of your tech stack.

Copy/paste code samples in your language
RESTful HTTPS endpoints with JSON
Real-time delivery receipts via webhooks
Multi-language documentation & guides
Test and go live in minutes
UK-based developer support
get api key view documentation
curl -X POST \
https://api.faretext.co.uk/v1/sms
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"to": "+447700900000",
"from": "MyApp",
"message": "Your code is 847291"
}'
$response = Http::withToken(
'YOUR_API_KEY'
)->post(
'https://api.faretext.co.uk/v1/sms',
[
'to' => '+447700900000',
'from' => 'MyApp',
'message' => 'Your code is 847291',
]
);
import requests
response = requests.post(
'https://api.faretext.co.uk/v1/sms',
headers={'Authorization': 'Bearer YOUR_API_KEY'},
json={
'to': '+447700900000',
'from': 'MyApp',
'message': 'Your code is 847291',
}
)
const response = await fetch(
'https://api.faretext.co.uk/v1/sms', {
method: 'POST',
headers: {
'Authorization': 'Bearer YOUR_API_KEY',
'Content-Type': 'application/json',
},
body: JSON.stringify({
to: '+447700900000',
from: 'MyApp',
message: 'Your code is 847291',
}),
});
600 msg/sec | 99.9% Uptime | Direct Routes | Free Support

Integration Patterns

Built for modern app architectures.

Multiple integration methods to suit your application's technical requirements.

RESTful API

Standard HTTPS endpoints with JSON payloads. Send, receive, and manage messages with simple API calls from any language or framework. Authentication via API key or legacy username/password.

Webhooks

Receive real-time delivery receipts and inbound messages via HTTP callbacks to your application. No polling required — we push events to your endpoint the moment they occur.

SMPP

For enterprise-grade throughput, our SMPP 3.4 integration offers sustained high-volume messaging with simultaneous delivery receipts. Ideal for applications sending millions of messages.

Email-to-SMS bridge

Route messages through our email gateway for applications that already use email as a notification channel. Convert any email output into an SMS with zero code changes.

Getting Started

Three steps to integrate.

From sign-up to sending your first message in minutes.

01

Create your account

Register via our connect page and choose API key authentication. You'll receive 25 free credits to test the integration with your application.

02

Receive your API key

Your unique API key is generated automatically and sent to you securely. Store it in your application's environment variables for secure authentication.

03

Integrate and go live

Use our code samples and documentation to integrate SMS into your app. Most developers send their first message within 15 minutes of receiving credentials.

create your account

FAQS

App Integration FAQs.

Integrate our SMS API into your app's backend. Your server sends HTTPS requests to our API endpoint with the recipient's number, your message, and your API key. We handle the delivery to mobile networks. This works with any tech stack — iOS (Swift), Android (Kotlin/Java), React Native, Flutter, or any server-side framework. The integration typically takes less than an hour with our code samples.
SMS 2FA significantly improves security compared to password-only authentication. While no single method is 100% secure, SMS-based verification is recommended by NIST as an acceptable second factor and is used by over 80% of businesses for identity verification. It works on every phone without requiring a separate authenticator app, making it the most accessible form of 2FA available. For most applications, SMS 2FA provides the right balance of security and user convenience.
Verification codes are typically delivered within 1-3 seconds. Our API processes requests instantly and routes messages directly to UK mobile networks — no queuing, no batch processing. This speed is critical for 2FA codes where users are waiting in real time. With 98.5% delivery rates on direct network routes and sub-200ms API latency, your users receive codes almost immediately.
Yes — and it's one of the smartest reliability strategies for app notifications. Push notifications fail silently when the app isn't installed, notifications are disabled, the phone lacks internet, or battery saver is active. SMS bypasses all of these limitations. Implement a fallback pattern: attempt push first, then send SMS if push delivery fails or isn't confirmed within your timeout window. This ensures critical messages always reach your users.
Our RESTful API works with any language that can make HTTPS requests — which is effectively every modern programming language. We provide ready-to-use code samples in cURL, PHP, Python, Node.js, Java, .NET/C#, and Ruby. Our documentation covers authentication, sending messages, receiving replies via webhooks, and checking delivery status. Most developers send their first message within 15 minutes.
Our API handles up to 600 messages per second with sub-200ms latency. For most applications, this is more than sufficient — even high-traffic apps rarely need to send more than a few hundred messages per second. For enterprise-scale requirements, our SMPP integration offers sustained high-volume throughput with simultaneous delivery receipts. If you need capacity beyond standard API limits, contact us to discuss dedicated routing.
When you rent a reply number from us, inbound messages are forwarded to your application via webhooks. We send an HTTP POST to your configured endpoint with the sender's number, message content, and timestamp. Your app can then process the reply — whether that's confirming a booking, updating a record, or routing to your support system. This enables two-way conversational messaging within your application.
There are no setup fees, no monthly charges, and no minimum commitments. You pay only for messages sent — typically 3-7p per UK SMS depending on volume. We provide 25 free credits when you sign up so you can test the integration at no cost. For high-volume applications, we offer competitive volume pricing. Visit our pricing page for current rates and volume tiers.

Related insights

Two-Factor Authentication by SMS: Still the World's Most Used Security Layer
Technology
Faretext Blog
Technology 05 Dec 2023

Two-Factor Authentication by SMS: Still the World's Most Used Security Layer

Despite debates about alternative methods, SMS remains the most widely deployed two-factor authentication channel. Google's research shows it stops 100% of automated attacks and 96% of bulk phishing.

read article →

3 min read

Ready to integrate SMS into your app?

Join over 400 UK businesses sending smarter with Faretext.

get api key view documentation

25 free credits to test. No contract. UK-based support.

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