Everything You Need to Know About SMS Verification

Diana Nersisyan
Diana NersisyanProduct Owner

Published: Dec 23, 2022

SMS Verification

Since its inception, SMS verification has changed the way we use the internet and live online. It has made it easier for us to stay connected while accessing information and services quickly and easily. Thanks to phone number authentication, the security of our online accounts has been immensely improved, making it easier for us to keep track of our online activity.

Despite the popularity of sending one-time passwords (OTPs) to mobile devices as a way to secure accounts, there are still many cases of account breaches. Surfshark reported that the United States had the largest number of breached users in 2021. A total of 212.4 million users were affected, compared to 174.4 million in 2020.

Iran came in second, with 156.1 million breached users in 2021 versus 1.4 million in 2020. This was perhaps the biggest jump in breaches year over year. This only goes to show that verifying with SMS is more necessary than ever. It creates more obstacles for hackers to overcome in order to breach your personal data.

What is SMS Verification

SMS verification is a process that involves the use of an OTP that is sent to a user's mobile device via texts. This password is then entered into an app or website that requires user verification. Two-factor authentication can be used to verify the identity of a user when they are trying to sign up for a new account, log in to an existing account, or make a purchase.

Mobile OTP authentication is a secure way to confirm a user's identity because the code is only valid for a single use. This means that even if a hacker were to intercept the code, they would not be able to use it to gain access to the account or make a purchase. An SMS verification service is also convenient for users because they do not need to remember a password or provide any personal information.

Is Sending OTP to Mobile Phones Safe

Sending an OTP SMS to phone numbers is a safe and secure way to keep your account information safe. By adding an extra layer of security in the form of an OTP, you can protect your account information from being compromised.

Verifying with text messages is actually one of the most secure methods available. This is because it uses a two-factor authentication system that requires both a physical device and a code to verify your identity. This means that even if someone were able to gain access to your physical device, they would still need your text-activated code in order to log into your account.

Text Message API Service Pricing

Dexatel employs a pay-as-you-go approach that charges you per sent message. This is the most affordable SMS gateway pricing model, and the service costs are free of setup, monthly, or any other fees.

Which Industries Need Texts to Verify Phone Numbers the Most

Banking and financial services

Texting is often used as a second factor of authentication for online banking and financial transactions.


Many online retailers use SMS to verify the phone numbers of new customers. This helps prevent fraud and ensures that only genuine customers can make purchases.

Food and beverage

Restaurants and other similar businesses often use SMS to ensure that orders are sent to the correct phone number and that customers can be contacted if there are any issues with their orders.


Texting is used by many healthcare organizations to verify patient phone numbers. This ensures that patients can be reached in case of emergencies and that appointments and other important information can be sent to the correct phone number.

How to Verify Users with SMS 

When you sign up for a new account on a website or app, you may be asked to provide your phone number as part of the process. Once you enter your phone number, you'll usually receive a message with a code that you'll need to enter on the website or app to complete the process.

These codes are typically 4–6 digits long, but some companies may use longer or shorter codes. The code is generally only valid for a few minutes, so you'll need to enter it quickly after you receive it.

In a nutshell:

  1. A user enters their phone number into a verification form on a website or app
  2. The website or app sends an SMS message to the user's phone number
  3. The user receives the SMS message and enters the code into the form
  4. The website or app verifies the code and allows the user to access the desired content

What Happens When You Don’t Receive the OTP Number

If you do not receive the OTP number, this means that either your mobile number wasn't entered correctly or your mobile network is not functioning properly. In this case, you may need to try a different method of verification, such as email or a phone call.

Advantages of Verifying with SMS

It’s Quick

SMS authentication is a very quick and easy way to verify someone's identity. This can be especially useful when you are trying to verify a large number of people in a short period of time.

It’s Convenient

Another advantage of SMS authentication is that it is very convenient for both the person doing the verification and the person being verified. The person being verified doesn't need to have their phone with them at all times, which can be a major inconvenience. All they need is their phone number, and they can receive the code whenever they need it.

It’s Secure

It goes without saying that verifying with texts is a secure method of authentication. The codes that are sent are unique to each individual and cannot be guessed. This means that it is very difficult for someone to fraudulently pretend to be someone else in order to gain access to someone else's account.

It’s Easy to Remember

In the past, we would've had to remember a username and password for every website or online service that we used. This could be difficult to keep track of, and if we forgot our login information, we would be unable to access our account. But thanks to this, we can receive a code every time we need to log in to a website, which makes it much easier to keep track of our online activity.

Is It Possible to Bypass Phone Number Verification?

Technically, yes, but it is not advisable. This is because bypassing phone number verification can lead to security and privacy issues because it is done with fake numbers.

Bypassing phone number verification can also lead to charges being applied to your account. Certain websites provide services with temporary numbers to bypass verification—again, this is not advised. They do so using virtual phone numbers that change every day to prevent another user from using the same number on the same web service.

While it may be tempting to bypass verification, this can have serious consequences. Bypassing verification with temporary phone numbers may allow someone to gain access to your personal information, which could lead to identity theft or other security issues. Moreover, disposable phone numbers can also allow someone to make unauthorized charges to your account.

SMS Text Verification Service With Dexatel

As with reminders, alerts, and text marketing messages, Dexatel allows you to send online mobile number verification SMS to your users. Upon signing up on our platform, you can send up to 30 free messages for testing

With Dexatel’s SMS service API, you can:

  • Send text messages in several formats
  • See the recipient's response
  • Personalize each message
  • Check the status of your messages

We offer:

How to Get Started With SMS Verification on Dexatel

We have a separate piece on how to send OTP SMS with Dexatel, but for a shorter version, check out the guide below.

1. Create an Account

Create an account on the Dexatel platform free of charge. Log in to your dashboard and manage your account settings, such as topping up your balance, updating information, monitoring statistics, and more.

2. Generate a Unique API Key

Then, go to the API Keys section. The system will generate a unique API key, which you will use as a credential to send automatic requests on your behalf.

3. Create a Sender Name

Add your brand or company name to the Sender IDs in the dashboard. Otherwise, you can send a POST request to the Sender endpoint so you can send OTP messages with a customized ID.

4. Get a Template ID

Go to the Templates page or send a POST request to the Template endpoint. Once a template is created, the API will generate a template ID for you to use. Another way to see your template ID is by sending a GET request to the Templates endpoint.

While creating a template text, you must include a {code} variable in it. The Dexatel Verify API will generate a random OTP and replace it in your message instead of {code}.

5. Ask for Your Clients’ Phone Numbers

Ask for your clients’ phone numbers to verify whether they actually belong to them by sending an SMS code. Once the code matches, the process will be completed. Otherwise, the code will expire and the user will be temporarily blocked after 3 unsuccessful attempts.