SmsGateWay24 Plateforme de communication client par SMS et WhatsApp

Send one-time passwords (OTP) over SMS

A one-time password is a short, single-use code you text to a user to prove they control their phone number. It powers two-factor authentication, login verification, password resets and payment confirmation — and it needs to arrive in seconds.

SmsGateWay24 delivers OTP codes straight through your own Android phone and SIM card. There is no reseller queue between you and the mobile network, so codes land fast, and you pay your normal carrier rate instead of a per-message markup.

Démarrer l'essai gratuit Open the API docs

How OTP over SMS works

Three steps, fully automated through the API.
1
Generate the code
Your app creates a random 4–8 digit code and stores it with a short expiry (typically 60–300 seconds).
2
Send it via the API
One API call hands the message to your Android device, which sends it through the SIM to the user's phone.
3
Verify the input
The user types the code, your app checks it against the stored value before it expires, and access is granted.

Send an OTP with one API call

Post the recipient number and your message to the send endpoint using your API token. Full parameters are in the API documentation.

curl -X POST "https://smsgateway24.com/getdata/addsms" \
  -d "token=YOUR_API_TOKEN" \
  -d "device_id=YOUR_DEVICE_ID" \
  -d "sendto=%2B4915112345678" \
  -d "body=Your verification code is 493028. It expires in 5 minutes."
Read the full SMS API reference

Fast delivery

Codes go directly from your SIM to the network, avoiding the aggregation delays that make OTP codes arrive late.

Predictable cost

You use your own mobile plan, so OTP traffic costs what your carrier charges — not a per-message OTP premium.

You stay in control

No sender registration and no third party reading your traffic. The device is yours and the number is yours.

Where OTP over SMS is used

  • Two-factor authentication on login
  • Confirming payments and high-value transactions
  • Password reset and account recovery
  • Verifying a phone number at sign-up

Frequently asked questions about SMS OTP

Most services expire a code after 60 to 300 seconds. A short window limits the time an intercepted code is useful while still giving the user time to type it.

Four to eight digits is standard. Six digits is the common balance between security and ease of typing.

No. OTP codes are sent through the same device, token and send endpoint as any other SMS in SmsGateWay24.

Yes. Delivery status is reported back to your dashboard and can be pushed to your server through webhooks so you know when a code reached the handset.

Start sending OTP codes today

Connect your Android phone and send your first verification code in minutes.

Démarrer l'essai gratuit Compare SMS types