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OTP SMS service for secure login and payments
An OTP (one-time password) SMS sends a short code to the customer's phone to prove who they are. It is used for login, sign-up, password reset and payment confirmation. SMSNiti connects OTP sending to your website or app through an API, registers the template and gives you delivery reports so you can see what reached the phone.
OTP messages are sent the moment they are requested and can reach numbers on the DND list.
- Sent the moment it is requested
- Simple API
- Reaches DND numbers
Overview
What is an OTP SMS?
An OTP SMS carries a one-time password: a short code, usually four to eight digits, that works once and expires within minutes. The customer types the code into your website or app to confirm that they hold the phone number. It adds a second step to a login or payment so that a stolen password alone is not enough.
Short answer: An OTP SMS is a text message containing a one-time code used to verify a person's identity for login, sign-up or payment. It is sent instantly, expires quickly and can reach numbers on the DND list.
Where OTPs are used
Banks, payment apps, online stores, delivery services, e-learning platforms and any business with customer accounts use OTPs. They are also used to confirm a new phone number during registration and to approve sensitive actions such as changing an address.
Why speed matters
An OTP is useful only while the customer is waiting for it. We keep the path short: your system calls the API, we hand the message to the operator at once, and you can see in your report whether it was delivered.
What you get
What you get with OTP SMS
Simple API
Call the API when a customer asks for a code. Our team helps your developers get connected quickly.Template guidance
We help you register an OTP template that follows the rules, with a variable for the code.Delivery reports
Check delivery status for every message in the panel.Sent immediately
The message goes out the moment your system triggers it.Reaches DND numbers
OTPs are messages the customer asks for, so they can be delivered to numbers on the DND list.Support when you need it
Reach our team if your customers report codes that did not arrive.How it works
How OTP SMS works in your app
Customer asks for a code
They enter their phone number to log in, sign up or pay.Your system creates the OTP
Your software generates a random code and stores it with an expiry time.You call our API
The API sends the code to the customer's phone using your approved OTP template.Customer enters the code
They type the code from the SMS into your page or app.You verify it
Your system checks the code and the expiry, then lets the customer in.Templates
Sample OTP SMS templates
OTP templates are short and use {#var#} for the code and, if needed, the purpose.
| Use | Sample template |
|---|---|
| Login | {#var#} is your login code for {#var#}. It is valid for {#var#} minutes. Do not share it with anyone. |
| Payment confirmation | Your code to confirm a payment of Rs. {#var#} is {#var#}. Do not share it with anyone. |
| Registration | {#var#} is your verification code to create your {#var#} account. |
Always remind people not to share the code. Your exact wording is submitted for approval, and we help you phrase it.
Security tips
How to use OTPs safely
The code is only as safe as the way you handle it.
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Short expiry: A code should expire within a few minutes and work only once.
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Limit attempts: Lock the request after a few wrong entries to stop guessing.
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Limit resends: Cap how many codes one number can request in an hour to prevent abuse and wasted cost.
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Never log codes: Do not store codes in plain text in logs or analytics.
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Tell people not to share: Add a line telling people never to share the code, even with someone claiming to be you.
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Plan a fallback: Offer a voice-call OTP or a WhatsApp OTP for customers who do not receive the SMS.
Who uses it
Where businesses use OTP SMS
Login and two-step verification
Confirm a returning customer on a new device.Sign-up and registration
Confirm that the phone number belongs to the person registering.Payments
Authorise a card or wallet payment with a code.Password reset
Let customers reset a forgotten password safely.Delivery handover
Share a code the customer gives the courier to confirm delivery.Account changes
Approve changes to an address, phone or bank detail.Why SMSNiti
Why choose SMSNiti for OTP SMS
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Quick integration: Our team supports your developers from the first test to go-live.
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Template approval help: We guide you through DLT registration of your OTP template.
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Visibility: Delivery reports help you answer "I did not get my code" tickets.
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More than SMS: Add WhatsApp OTP or voice OTP as a fallback with the same partner.
Questions
OTP SMS: frequently asked questions
OTP SMS is a text message that carries a one-time password, used to verify a customer during login, sign-up or payment.
Yes. OTPs are requested by the customer, so they can be delivered to numbers on the DND list.
Yes. Your business, sender ID and OTP template are registered under DLT before you can send. We guide you through it.
A few minutes is typical. Short expiry reduces the risk if a code is intercepted.
Common reasons are poor network coverage, a switched-off phone, a wrong number or a blocked sender. Your delivery report shows the status, and our team can help investigate.
Yes. You can offer WhatsApp OTP or a voice call as a fallback for customers who do not receive the SMS.
Yes. Our API connects to websites and mobile apps, and our team supports your developers.
Yes. We recommend limiting resends and attempts in your own system to prevent abuse. We can advise on sensible limits.
Pricing depends on how many OTPs you send. Request a quote and we will suggest a plan.
Talk to a messaging expert today
Tell us what you want to send and who to. We will suggest the channel and the plan.
