Title: SMS OTP URL: https://www.infobip.com/sms/otp # Secure user logins globally with Infobip’s SMS OTP service Authenticate users instantly with the world’s most reliable SMS OTP verification API. Easily reach mobile users globally through Infobip’s 800+ direct telco connections. [ Get your API key ](/signup?signup_source=InfobipProductPageSMS) [ Contact an expert ](/contact) Sign up to get your API key. See how to get started with Infobip APIs. POWERING CRITICAL COMMUNICATIONS FOR GLOBAL BRANDS ## Why brands trust Infobip for authentication via SMS Every day, our SMS OTP platform helps protect millions of user logins all around the world. With high delivery rates and proven reliability, we help brands keep accounts safe and make sure users can always get access when they need it. ### Unrivaled delivery rates Don't let lost codes hurt your conversions. Our network of direct connections ensures messages arrive in seconds, not minutes. ### Bank-grade security Fully compliant with GDPR, ISO 27001, and SOC 2. We mitigate fraud with short expiry times and rate limiting. ### Global reach, local feel Send OTPs to any mobile number, using local branded sender IDs your users trust and recognize instantly. ## Built for developers, scaled for enterprises - **Smart fallback logic**: If one channel fails, automatically retry via others. Ensure 100% verification success. - **Real-time analytics**: Monitor delivery speeds and conversion rates instantly. - **Flexible configuration**: Customize code length, expiry time, and retry limits. [ Sign up to get your API key ](/signup?signup_source=InfobipProductPageSMS) [ More about our SMS API ](/sms/api) ``` code goes here ``` ## Customer stories From fintech to entertainment, brands across the globe trust Infobip platform to secure their user experience. ## Verify users via SMS in 4 simple steps ![Sign-in screen with fields for username and password, offering options to sign in, including receiving a verification code.](https://cdn-web.infobip.com/uploads/2025/03/sms-otp-initation.png) 1. TRIGGER ### User request User triggers the process by requesting a login or verifying a transaction on your website or app. ![Text message stating: 'Your one-time PIN code is 635606. Please type this code in your app to complete the verification.](https://cdn-web.infobip.com/uploads/2025/03/sms-otp-received.png) 2. GENERATE ### Code generation The API call generates a secure, randomized, time-sensitive code sent to the user. ![Screen prompting to enter a 6-digit code received via SMS, with the code '635606' entered and a 'Verify' button below.](https://cdn-web.infobip.com/uploads/2025/03/sms-otp-enter.png) 3. DELIVER ### Message delivery Infobip routes the SMS with the generated code via the fastest direct path to the user. ![Screen displaying a checkmark with the word 'Verified', indicating successful verification.](https://cdn-web.infobip.com/uploads/2025/03/sms-otp-verified.png) 4. VERIFY ### User verification User gets access to your platform after entering the code. ## Examples of SMS OTP use cases ### Public services Authenticating personnel accessing critical systems (e.g. police and fire departments or emergency response teams). ### Delivery services Verifying personnel and ensuring secure package handling. ### Educational institutions Securing access to student portals, course registrations, and academic resources. ### Hotels and airlines Enhancing security during online bookings, reservation changes, and loyalty program interactions. ## Why SMS OTP remains the standard Use SMS for maximum reach, and layer other channels for cost optimization. SMS OTP Email OTP WhatsApp OTP **Reach** 100% (any phone) High Only app users **Speed** Instant Slower (due to spam filtering) Fast (if internet connection stable) **Internet connection required?** No Yes Yes **Best for** Primary two-factor authentication Backup 2FA Cost savings (with fallback) ### Expand your messaging channel mix – maximize conversions, minimize costs Send time-sensitive OTP messages on the most cost-effective channel for each recipient, with failover safeguards that never let you down.  [ Explore Smart Messaging ](https://www.infobip.com/smart-messaging) ## Recognized for reliability, security, and reach Our OTP SMS service received widespread recognition within the industry, being awarded for its reliability, security, and global reach. As a trusted provider, these awards reinforce our devotion to providing top-tier security solutions that businesses can rely on. ![](https://cdn-web.infobip.com/uploads/2024/12/iso.svg)### ISO 9001 Certified [ View certificate ](https://cdn-web.infobip.com/uploads/2025/02/infobip-certificate-iso.pdf) ![Certificação A-Lign Iso 22301.](https://cdn-web.infobip.com/uploads/2023/07/ISO-22301-INFOBIP.png)### ISO 22301 Certified [ View certificate ](https://cdn-web.infobip.com/uploads/2024/08/22301-Certificate-INFOBIP-LIMITED-2024.pdf) ![Certificação AICPA/A-Lign SOC 2 Type One Report Compliant.](https://cdn-web.infobip.com/uploads/2023/07/Aicpa-SOC-and-SOC-2-INFOBIP.png)### SOC 2 Type 2 compliant ![Certificação Mobile Ecossustem Forum com a Trust In Enterprise Messaging.](https://cdn-web.infobip.com/uploads/2023/02/TEM-INFOBIP.svg)### Mobile Ecosystem Forum certified ## How to choose an SMS OTP provider Choosing the right SMS OTP provider is crucial for ensuring security and reliability of the authentication process. Let’s explore the key criteria you should consider before deciding: ### Deliverability and speed Look for providers that offer guarantees in delivering SMS messages promptly to customers. Delays in OTP delivery can impact user experience and security. ### Security features Evaluate the encryption methods used by the provider. Strong encryption ensures that OTPs remain confidential during transmission. Consider data protection mechanisms, such as secure storage of phone numbers and OTPs. Ensure the provider complies with relevant regulations (e.g., GDPR, CCPA) to safeguard user privacy. ### Integration Assess how easily the SMS OTP solution integrates with your existing systems. A seamless integration process minimizes disruptions and saves time. Check if the provider offers APIs or SDKs for smooth implementation. ### Pricing Compare costs among different providers, considering initial setup fees and ongoing charges. However, note that a lower price might mean lower-quality SMS routes, which could lead to OTPs not being delivered. Scalability is essential—ensure the pricing model aligns with your expected growth. ## Frequently asked questions about SMS OTP Yes. When implemented with best practices, such as short expiry times and rate limiting to prevent brute force attacks, it is a secure standard. Infobip also offers Signals, a product that uses machine learning to detect and block artificial traffic and SMS pumping fraud to further enhance security. Our system handles this using smart fallback features. If an SMS fails to deliver (e.g., due to network issues), the API can automatically retry via alternative channels like Voice or Email to ensure the user is never locked out. You can also configure specific failover logic, such as failing over from RCS to SMS, to guarantee delivery. Read more about failover API setup here. An OTP, or one-time password, is a temporary code generated by a system and used to verify a single login session, transaction, or action. 2FA (Two-Factor Authentication) is the general security process that requires two forms of identification (e.g., your password + the OTP). OTP codes are one of the most popular methods of implementing 2FA. In case of SMS OTP, an SMS message is simply the delivery channel for the OTP code. You can also send OTP codes via other channels, like WhatsApp OTP, RCS OTP, or Viber OTP. Yes. Infobip's 2FA API lets you verify users via SMS, Email, and Voice. This allows you to create "smart routing” strategies—for example, use a Email or App push first, with SMS as a high-reliability backup. Read more about our 2FA API here. ## Reinforce security and build trust with Infobip Start sending secure OTPs via SMS in minutes. [ Sign up to get your API key ](/signup?signup_source=InfobipProductPageSMS)[ Contact us ](/contact)