Live · India · Airtel, Vi, Jio

Verify a phone number
without OTP.

SNA verifies a user's mobile number directly with their telecom operator - no OTP, no tap, no app switch. The user enters their number, and they're in. Authentication completes in under a few seconds, at the network layer, with proof of SIM possession that no SMS code can match.

See the flow → Read the technical spec
≤ 4s
P90 verification
85-95%
SNA success rate
15-20%
Conversion lift
0
Permissions required
Silent Network Auth · demo
1
User submits number
SDK takes mobile as input and generate the SNA Telco URL (No PII in URL)
2
SDK opens an SNA URL on cellular
The device makes a direct, SIM-bound HTTP call to the operator. Wi-Fi is switched off for this hop.
3
Operator validates SIM & network
Cross-references IP, port, and network bindings. Confirms or denies — silently.
4
OTPless issues an auth token
Server-to-server fetch confirms the result. We hand you a verified auth token.
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The problem with OTPs

OTPs lose 25% of users at the front door.

For a decade, the industry pretended OTP was a UX problem worth living with. It isn't. It's the single largest source of drop-off in mobile sign-up, and the most frequently exploited surface in fraud.

SMS OTP

The default - and the bottleneck
  • Delivery fails or arrives late on every login
  • Users mistype, miss the timer, or app-switch and lose context
  • Phishable, SIM-swappable, socially engineerable
  • One provider outage halts every login

Silent Network Auth

The replacement - invisible by design
  • Verifies in under four seconds, at the network layer
  • Zero user action - no code, no tap, no app switch
  • Validates SIM possession; phishing surface is gone
  • Multi-operator routing with automatic fallback
Telecom-grade flow

How it actually works.

SNA is a real telecom protocol. OTPless abstracts it behind a single SDK call. Here is exactly what runs underneath - every actor, every hop, every guarantee.

End userPhone
OTPless SDKClient device
OTPlessBackend
TelcoAuth gateway
TelcoCore network
01
App → OTPless
User submits a phone number in the customer app. The SDK posts the number to the OTPless edge over TLS. Identity is sent hashed + anonymized.
02
OTPless → SDK
OTPless identifies the operator from MCC/MNC, generates a one-time SNA authentication URL, and returns it with an opaque_token. No PII is embedded in the URL.
03
SDK → Operator (cellular only)
Device opens the SNA URL on the cellular interface. Wi-Fi is bypassed automatically - SIM-based network identity (IP, port, network bindings) is the validation surface.
04
Operator (silent validation)
Operator confirms SIM is active, the network identity matches the device, and updates verification state internally. No screen, no consent, no user-visible event.
05
OTPless ↔ Operator (S2S)
After page load, OTPless fetches the result via a server-to-server API call. Operator returns a yes / no. Nothing more.
06
OTPless → Customer backend
If verified, OTPless issues a signed auth_token. Your backend validates and creates a session. Total wall-clock: under four seconds at P90.

Why mobile data, not Wi-Fi? Validation depends on SIM-bound network identity. Wi-Fi masks the SIM, so the operator can't verify the device. The OTPless SDK auto-detects connectivity and routes the SNA call over cellular even when the device is on Wi-Fi.

Operator coverage

Live across India. Expanding globally.

38+ countries live · ~95% population coverage in India · operator-level details per market on request.
Vodafone-Idea
Live
Reliance Jio
Live
Bharti Airtel
Live
Global footprint
🇺🇸United States
🇬🇧United Kingdom
🇩🇪Germany
🇫🇷France
🇪🇸Spain
🇮🇹Italy
🇳🇱Netherlands
🇸🇪Sweden
🇳🇴Norway
🇩🇰Denmark
🇫🇮Finland
🇮🇪Ireland
🇵🇹Portugal
🇨🇭Switzerland
🇦🇹Austria
🇧🇪Belgium
🇵🇱Poland
🇨🇿Czechia
🇸🇬Singapore
🇲🇾Malaysia
🇮🇩Indonesia
🇵🇭Philippines
🇹🇭Thailand
🇻🇳Vietnam
🇯🇵Japan
🇰🇷South Korea
🇭🇰Hong Kong
🇹🇼Taiwan
🇦🇺Australia
🇳🇿New Zealand
🇦🇪UAE
🇸🇦Saudi Arabia
🇿🇦South Africa
🇳🇬Nigeria
🇰🇪Kenya
🇧🇷Brazil
🇲🇽Mexico
🇨🇦Canada
UPI SIM BINDING

NPCI-approved for UPI SIM Binding.

Every UPI account must be bound to the SIM that holds the registered mobile number. The legacy flow sends an outbound SMS from the device - opaque, slow, and the single largest source of drop-off during onboarding. SNA replaces that handshake with a silent, network-layer SIM check.

+30%
Onboarding conversion lift
vs. outbound SMS binding
−85%
SIM-swap & spoofing fraud
measured on first-time binding
≤ 3s
P90 bind time
silent, no SMS sent
  • NPCI Approved. Cleared by NPCI as an SMS-binding alternative for UPI handle issuance — production-ready on the telecom rails.
  • No reliance on the SMS protocol. No dependency on an SMS pack - SNA uses the data network to authenticate, not SMS.
  • No permissions required. Zero SMS-read, SIM-state, or phone-state permissions on the device. Nothing to consent to.
  • Stronger security. SIM-swap and spoofing surface collapses - the bind only succeeds if device, SIM, and registered MSISDN are all present together.
UPI SIM BINDING · SILENT NETWORK AUTH SECURE
  1. 01
    User enters mobile in the UPI app
    No outbound SMS, no permissions prompt.
  2. 02
    SNA verifies SIM at the operator
    Operator confirms the SIM matches the MSISDN — silently.
  3. 03
    Bank receives a signed bind token
    PSP / bank validates the token and proceeds with VPA creation.
  4. 04
    UPI handle bound to the verified SIM
    Account ready · audit trail preserved · no SMS sent.
Status NPCI APPROVED
Prashant Pandey, Engineering Manager at Navi
Prashant Pandey
Engineering Manager

From talks to go live in 24 hours. We evaluated multiple SMV vendors before going with OTPless. The difference was clear - 4–5% higher success rates compared to other vendors we tested, which at our scale is significant.

What stood out was how they showed up. Their team was in our office throughout the integration. Support was instant, never had to chase anyone. We went live faster than expected.

When SNA can't run

When SNA can't run, fallback is automatic.

Some sessions can't be verified silently - the SIM is suspended, mobile data is off, the operator isn't supported. Smart Auth catches every one of those cases and recovers them, in a single API request.

×

SIM inactive or suspended

Operator returns a negative validation. Smart Auth routes immediately to the next channel.

⤬

No mobile data active

SDK detects the missing cellular path and fails fast. Fallback fires before the user notices a delay.

∅

Operator not supported

Outside our coverage list, SNA never runs. The user takes the WhatsApp or SMS path on the first attempt.

FALLBACK CHAIN SNA → WhatsApp → SMS → Voice See Smart Auth orchestration →
On this page
  1. 01 Flow
  2. 02 Why SNA
  3. 03 Sequence
  4. 04 Coverage
  5. 05 UPI SIM Binding
  6. 06 Fallback
  7. 07 Security
  8. 08 FAQ
Security & compliance

More secure than SMS OTP.

SNA is more secure than SMS because there's nothing to phish, intercept, or forward. Validation happens directly with the telecom network, against active SIM possession.

No OTP exposure

Eliminates phishing, social engineering, and OTP forwarding - there is no code in the wire.

No PII shared

Phone numbers are passed to operators hashed and anonymized. The operator returns yes / no.

RBI / NPCI reviewed

Built on telecom-approved rails. Has cleared regulatory security validation in India.

No permissions

No SMS read, no SIM info, no phone state. Only an HTTP allowlist for the telecom domain.

Frequently asked

Common questions.

Does SNA work on both Wi-Fi and mobile data?
SNA requires the cellular interface because validation is based on SIM-linked network identity. If the user is on Wi-Fi but mobile data is also enabled, the OTPless SDK automatically routes the SNA call via the mobile network. Mobile data must be active even if Wi-Fi is connected.
Is the user's mobile number or any PII shared with the operator?
No direct PII. When OTPless fetches the status from the telecom, the mobile number and IP address are passed in a hashed and anonymized format. The operator simply responds with a yes / no.
Does the user see a pop-up, redirect, or consent screen?
No. SNA is a fully silent flow. There is no OTP, no pop-up, no consent screen, and no user action required during authentication.
What happens if SNA fails for a user?
Smart Auth automatically routes to the best fallback for that user and network - WhatsApp OTP, SMS OTP, or Voice OTP - in the same request. Drop-off is eliminated end to end.
Why can't SNA cover 100% of users?
Coverage depends on operator support, device conditions, and telecom regulations. SNA cannot run when the SIM is inactive or suspended, mobile data is off, the operator isn't supported, or the user is in roaming or a restricted network.
How does SNA compare to OTP on security?
Stronger. There is no OTP that can be phished, intercepted, or forwarded. Authentication happens directly with the telecom network and validates SIM possession + active network presence. The solution has cleared security review with RBI / NPCI.
Do we integrate separately with each operator?
No. OTPless provides a single SDK and API that works across operators. You don't need individual operator integrations, approvals, or contracts.
Which platforms does SNA support?
Android (native), iOS (native), and hybrid frameworks: React Native, Flutter, and Ionic. Web is not recommended in India because telecom-based validation uses HTTP-based header enrichment APIs.
What permissions does the SDK need?
None. SNA does not require SMS read, SIM info, phone state, or any sensitive permissions. The only requirement is a network security configuration to allow a restricted clear-text HTTP call to a whitelisted telecom domain.
Does SNA work for dual-SIM users?
Yes. The telecom network validates the SIM associated with the active mobile data slot. The OTPless SDK routes the request to maximize success.
Can we A/B test SNA before full rollout?
Yes. Roll out to a percentage of users, or to selected cohorts (e.g. Android only). Configure entirely from the dashboard - no code change required to ramp up.
Are there per-attempt charges?
Yes. SNA uses a telecom API, so each authentication attempt incurs a charge regardless of success. OTPless reduces cost by pre-validating signals to avoid false attempts and maximizing success before making the call.

Stop sending codes. Start verifying silently.

30-minute SDK integration. SNA, fallback channels, and Smart Auth orchestration - out of the box.

Talk to our team →