Although the internet comes with an unending stream of benefits, we cannot deny that it has become an effective tool for frivolous individuals to steal the data of people and siphon funds. Companies worldwide constantly face ransomware and phishing attacks that jeopardize their business. This not only disrupts the flow of online services but also discourages customers from such services. In the US alone, the first half of 2022 saw 53 million individuals fall victim to cyber-crime in one way or another, highlighting the need for a secure method of storing data.

Are you looking for a cheap and effective means of enhancing the security of your business? One that will protect the data of your customers and cement their trust in your company? A robust SMS OTP system will do the job.

What is SMS OTP?

OTP is an acronym for one time passwords, which are automatically generated during a login process and sent to a user’s phone number. In simple terms, SMS OTP is an SMS message that contains an OTP or OTP code. They usually consist of a string of characters(numbers, letters, and symbols).

How SMS OTP Codes Work

When a user attempts to log in on a website through their account, the system generates a security code, a one-time password that expires within a certain period after the user receives it. The OTP SMS message is sent to the user’s mobile number once the user enters the username and default password. After which, the user must enter the code for the access request to be granted.

This verification method adds an additional layer of security to users’ account and goes a long way in preventing fraudulent activities.

One Time Password Through SMS 

Sending one time passwords through SMS has become the norm for companies all over the world. SMS messages are faster to send and receive and have an incredible 98% open rate. This and the personal nature of an SMS message have made the SMS the perfect means of sending an OTP code for verification. You can even insert a URL link in addition to the security code so the user can quickly log in to make necessary changes, like updating passwords, in case the initial request to access the account was not made by the user.

One Time Password Through Voice

An alternative to SMS OTP is verification through voice. In this method, the one time passwords are recorded, and the person receives them via a direct call to his phone number. Unlike the SMS OTP, the code will not be stored on the user’s phone. One time passwords work best for customers with limited sight, and it is also advisable to activate them as a backup in case the SMS fails to deliver on time.

Benefits of Using OTP for Authentication Through SMS

You get a lot of benefits from using SMS OTP for authentication and verification of accounts on your website. Here are the top 5 benefits of using SMS OTP codes.

Extra Security 

SMS OTP provides extra security for the accounts of users on a company’s website or app. One way or the other, an unknown person or even someone you know can have access to your user name and password. But the only way a person can log in to your account is for them to have access to your phone and SMS messages.

With an SMS verification, customers are always notified of suspicious activity on their accounts. Knowing their account and data are always secure gives customers an additional layer of security and confidence.

Easy Accessibility 

The use of mobile phones is universal! People check their phones all the time. Also, it is a fact that SMS is the fastest way to reach out to a customer. Users are certain to receive the one time passwords at any time of the day when sent via SMS.


What easier way is there to get a user to confirm a login request than through the user’s phone? And what’s more, SMS is direct and fast. Users will not need to enter into any other application, nor is it a must for them to have mobile data. They only need to check their phone’s inbox and retrieve the one time passwords . 

This is not only convenient for customers but also for the sender. An SMS OTP system makes it cheap and easy for organizations to send one time passwords anytime the need arises.


It costs almost nothing to set up an SMS OTP service. In fact, setting up is absolutely free. You’ll only be charged for the SMS messages you send to customers. This applies not only to the senders but also to users who receive the message. They will not have to burn their data or be charged for receiving an SMS message. 

Cost-effectiveness is one of the most attractive aspects of security, which is why so many banks and financial institutions around the world are using SMS OTP authentication to secure transactions.

Accurate Database

Many companies tend to have an enormous database with various wrong information about their customers, especially when it involves figures(like a phone number). This mostly arises as a result of errors and negligence on the part of the customers during registration. SMS OTP helps to reduce these errors, thereby strengthening your software. How? You may ask.

It goes like this. When registering on a website, users are usually provided with a data page where they have to input their details, one of which is their phone numbers. You can immediately confirm if this information is valid through an SMS OTP. All you have to do is send a confirmation code to the provided phone number, which the user must input before their information is saved.

How to get Started With SMS OTP 

Every client or customer only wants to do business with a company that they can trust, a company whose software is secure. They want to have the assurance that any personal information or data shared with the company during registration or in the course of the business is safe. Hence, the need for a reliable SMS OTP service like There are many companies offering SMS OTP services, but the question is, can they really be trusted with the delicate affairs of your customers? At Textback, we do the job right and give you absolute value for your money. Book a demo with us to learn more about our amazing services and see if they are the right fit for you.

First, you have to decide whether you want to build your SMS OTP system and whether you’d generate your unique code yourself or if you prefer to have everything done for you. If you’d like to have everything done for you, you’d better opt for our complete package solution

Complete package solutions are usually very easy to deploy. They are fast and will not require much of your attention but are more costly. Another thing is that they have a rigid structure. There isn’t much choice, and you can’t be flexible with it.

Building a new system, on the other hand, will give you full control, and you’ll have the chance to be flexible with your SMS OTP codes, but they aren’t quite as fast and will take you more time since you have to build the whole infrastructure from the ground up. The most important thing is to consider the costs of development and maintenance before making a decision.

Have you made a decision yet? Would you like to build your OTP SMS system? You can do that with our trusted SMS API! Meanwhile, if you’re still having doubts or wondering if you’d be able to handle your system, you can take advantage of our free trials. You can also email us if you need our help making the right decision. We are available 24/7 and will do well to make you understand all you need to know.

How to Generate and Validate OTP 

Generating and validating OTP codes are incredibly simple and straightforward. And it only takes less than a minute! Here’s a quick rundown of the process to show how effortless it is.

  • Step 1: The user inputs username and password. This will prompt a request for an OTP.
  • Step 2: SMS API will be triggered, after which it will generate a one time code
  • Step 3: The code is sent via SMS to the user’s registered phone number.
  • Step 4: The user receives and enters the password online.
  • Step 5: SMS API will now verify the code and confirms access.

How Does One Time Password API Work

An API is responsible for the generation and validation of an SMS OTP. How it works is very simple. When users enter their username and original password online, the application calls the API to generate and send an OTP to their phone number. The API will obey the command and generate a code based on the setup software. It will then send the code to the provided phone number of the user. Once the user enters the given password, the API determines if it matches and grants access.

Examples of one time Password Authentication SMS

Below are standard examples of a one time password authentication SMS to help you get started.

  • Dear customer, your OTP for registration is 556828. Use the password to complete your login process.
  • Dear customer, use the OTP below to log into your account securely. 
  • OTP: 266464
  • Here’s your OTP to complete your transaction; 556431

SMS OTP Best Practices

One time passwords are usually generated online, so they are more secure than the password created by the user. Just like adopting best practices for SMS marketing campaigns, certain measures need to be implemented to solidify security with SMS OTP. Here are the top best practices you can use to ensure security and ease of use.

  • Always put the OTP in focus so the user can easily identify it. One easy way to achieve this is to highlight or bold the OTP.
  • The OTP should be six to ten characters long. This prevents people from accessing the account just by guessing the code.
  • Use a reputable and up-to-date OTP service to ensure fast transmissions. 

How Textback can help you with SMS OTP Implementation and Setup

Did you know that you can integrate OTP into existing systems? Textback has a powerful API that you can easily integrate into your system. Customize OTP codes, validate every code, and indicate a specific expiry time for every SMS OTP.

Two-factor authentication is the best way to protect your software, data, and browser. Many top companies in the world now use two-factor authentication in financial transactions, especially those that are sensitive and require verification. Send us an email at or contact our engineering team for a hands-on demo to build your SMS OTP system and provide customers with an exceptional user experience.


How long is an OTP valid?

OTP codes are designed for temporary use. They can only be used once and are not transferable. Most SMS OTP is only valid for only a minute or two. A new one will be generated if there is a need for it.

Is SMS OTP safe?

Yes, SMS OTP is safe. Choosing a reliable SMS OTP service prevents any vulnerabilities, interceptions and attacks from third parties during operations.

How can I use SMS OTP?

You can use SMS OTP to confirm customers’ details like phone numbers, usernames, and app passwords during registration. SMS OTP is also useful in activating bank payments, confirming transactions, recovering lost passwords, unifying government services, limiting access to personal or secret information, checking unfamiliar devices, alerting users of suspicious activity within their account, etc.