Send OTP: Tips and Best Practices for India

Profile Headshot of Satyam Gupta
Satyam Gupta

mins read

September 8, 2023


Key Takeaways

  1. OTP SMS has multiple use cases including 2FA, phone number verification, account recovery etc.
  2. Some best practices for sending OTP SMS include its format, readability, validity time etc.
  3. There are various business benefits of an optimized OTP SMS
  4. Simplified and seamless user flow reduce the chances of errors, lower the system load and enhance security
  5. Verify Now is an OTP SMS provider by Message Central which provider dedicated operator connectivity and flash speed OTP SMS

In today's digital age, OTP (One-Time Password) SMS has become a standard method for authentication in various online transactions and services. Whether it's OTP verification, two-factor authentication, phone number verification, account recovery, or payment confirmation, OTP SMS plays a crucial role in ensuring the security of user data and preventing unauthorized access.

However, the design and implementation of OTP SMS forms can greatly impact user experience. It's essential for product designers and developers to optimize the SMS OTP process to provide a seamless and secure user journey. In this article, we will explore best practices for OTP SMS forms, highlighting the importance of user-friendly design and secure implementation.


Understanding the Use Cases for SMS OTP

Before delving into the best practices, let's briefly review the common use cases for OTP SMS:

  1. Two-Factor Authentication: In addition to traditional username and password credentials, SMS OTP adds an extra layer of security by requiring users to enter a one-time password sent to their registered phone number.
  2. Phone Number Verification: Some services use a user's phone number as their primary identifier. SMS OTP is utilized to verify the ownership of the phone number, often combined with a PIN for two-factor authentication.
  3. Account Recovery: When users lose access to their accounts, OTP SMS can serve as a method for account recovery. By sending an OTP to the user's registered phone number, they can regain access and secure their account.
  4. Payment Confirmation: Payment systems, such as banks or credit card issuers, often require additional authentication for security purposes. OTP SMS is commonly used to confirm payments and ensure the transaction is authorized by the account holder.

Now that we have an understanding of the use cases, let's explore the best practices to optimize SMS OTP forms for these scenarios.

Best Practices for OTP SMS Forms

To enhance user experience and security, consider implementing the following best practices when designing SMS OTP forms:

1. Format of the OTP SMS

To improve the user experience and ensure secure OTP entry, it's essential to format the SMS text in a standardized and consistent manner. Following the origin-bound message format is recommended. The OTP SMS message should end with the receiver domain preceded by @ and the OTP preceded by #. Here's an example of the SMS text format:

Your OTP is 123456 #123456

This format allows browsers to associate the OTP with the specific domain, preventing phishing attacks and enhancing security. Moreover, consistent formatting facilitates reliable extraction of codes from SMS messages.

2. Chunking OTP Numbers for Readability

To enhance the readability and usability of OTP numbers, consider chunking them into easily readable and shareable formats. For instance, instead of displaying the OTP as a continuous string, divide it into chunks. For example, the OTP "456787" can be represented as "45 67 87." By presenting the OTP in this format, users can comprehend and recall the numbers more easily. Here are some recommended formats: "xxx xxx," "xx xx xx," "xxxx xxxx," or "x x x x x x" (where "x" represents a number).

3. Extended OTP Validity Time

To optimize user experience and reduce system load, consider extending the validity time of OTPs within the regulatory framework and local laws. Longer validity times allow users to complete parallel tasks without the risk of OTP expiration. However, it's important to note that certain critical transactions may require shorter validity times for security reasons.

4. Mapping User Interface and OTP SMS Format

To avoid confusion and errors, ensure that the user interface displays the same format as the OTP SMS message. Consistency in formatting is crucial to minimize user errors during OTP entry. For example, if the interface displays the OTP as "XX XX XX," make sure the SMS message follows the same format.

5. Avoid Alphanumeric and Three-Digit Codes

To prevent confusion and potential mix-ups, avoid using alphanumeric codes for OTPs unless necessary for high-security scenarios. Alphanumeric codes can be prone to errors and may cause users to mistakenly enter CVV codes or other similar codes. Similarly, three-digit codes should be avoided to minimize confusion with other numeric inputs in payment interactions.

6. Prioritize OTP in SMS Text

To improve user convenience and accessibility, start the SMS text with the OTP itself. This allows users to view the OTP via message previews, even when their phone is locked or when notifications are visible on desktop or tablets. However, it's important to consider potential privacy and theft issues associated with displaying the OTP upfront.

7. Avoid Placing Other Numeric Codes Next to OTP

To reduce user confusion and potential errors, refrain from including other numeric codes or information adjacent to the OTP in the SMS message. Placing multiple numbers or codes in close proximity can lead to misinterpretation and increase the likelihood of entry errors. Keep the OTP section separate and distinct from other information in the message.

8. Steer Clear of Doubles and Triple Series

While it may seem visually appealing, using doubles or triple series in OTPs can introduce errors during manual entry. Users may unintentionally repeat the same number or series, resulting in failed authentication attempts. To ensure a smooth user experience, avoid using repetitive patterns or series in OTPs.

9. Secure Delivery of OTP via Voice Calls or Email

When delivering OTPs via automated voice calls, utilize the recency effect to reinforce the code in the user's memory. Begin the call by providing context and instructions, and then repeat the OTP without requiring customer prompts. This approach minimizes cognitive load and improves the chances of accurate OTP entry. Similarly, for email-based OTPs, consider placing the code in the subject line for faster access without the need to open the email. However, be cautious of potential theft issues if the code is visible in notifications on various devices.

By implementing these best practices, you can enhance user experience, minimize errors, and improve the security of SMS OTP forms. Remember to align these practices with your specific business context, local regulations, and security requirements.

Business Benefits of Optimized SMS OTP Forms

Optimizing SMS OTP forms can yield several benefits to your business:

  1. Reduced User Errors: User-friendly design and clear formatting of OTPs minimize user errors during entry, resulting in a smoother user experience. This, in turn, reduces frustration, increases user satisfaction, and encourages continued engagement with your product or service.
  2. Lower System Load: By implementing longer validity times for OTPs, you can reduce the load on SMS systems and validation services. This optimization is particularly crucial when dealing with a large user base, ensuring efficient processing of OTPs and minimizing delays.
  3. Faster Task Completion: Well-designed and optimized SMS OTP forms enable users to complete tasks more quickly, resulting in higher conversion rates and increased revenue. Simplified authentication processes contribute to a seamless user experience and stronger brand loyalty.
  4. Enhanced Security: Following best practices for SMS OTP forms helps protect user data and prevent unauthorized access. By adhering to secure delivery methods and consistent formatting, you can mitigate the risk of phishing attacks, fraud, and identity theft.
  5. Inclusivity and Accessibility: User-centric design principles benefit individuals with disabilities and older adults, allowing them to engage with your product or service more easily. By prioritizing user experience and security, you create an inclusive environment that accommodates a diverse range of users.

By adopting these best practices, you can optimize the SMS OTP experience, strengthen security measures, and foster trust among your users. Remember to continuously evaluate and refine your SMS OTP forms based on user feedback and evolving industry standards.

We also have a detailed guide on the best practices for implementing OTP verification. You can check out the guide and take an informed decision.

OTP SMS Provider in India

Verify Now is a trusted OTP SMS provider in India with direct operator connectivity. The platform ensures instant OTP SMS delivery in India at unbeatable rates. It provides the best routes for high success rates and deliverability.

You can get started for free or talk to the team.

We also have a detailed guide on how to select the best OTP service provider for reference.


SMS OTP forms play a vital role in securing online transactions and protecting user data. By implementing best practices for SMS OTP design and delivery, you can enhance user experience, improve security measures, and foster trust among your users. Remember to prioritize user-friendly design, consistent formatting, and secure delivery methods to optimize the SMS OTP process. Regularly evaluate and refine your SMS OTP forms to ensure they align with evolving industry standards and user expectations. By prioritizing both user experience and security, you can create a seamless and trustworthy environment for your users.

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