Silent Network Authentication (SNA) is a next-generation approach to verifying phone numbers without relying on one-time passwords (OTPs). By leveraging mobile network infrastructure, SNA eliminates friction in onboarding and authentication flows while raising the bar for security.

As fraud tactics evolve and user expectations rise, businesses need verification methods that are faster, safer, and more reliable. SNA delivers exactly that. And with Prelude, companies can implement SNA today — with intelligent fallback to SMS or third party apps like WhatsApp OTPs where silent verification is unavailable.

What is Silent Network Authentication?

SNA is a carrier-based verification method that confirms a user’s phone number directly through the mobile network. Instead of sending an OTP, the carrier validates the SIM and device against the number provided.

Key characteristics:

• Invisible to the user: Eliminating OTP SMS code inputs means smoother verification, noticeably less friction, and stronger conversion rates.

• Network-level security: Verification runs directly through carrier APIs, making it resilient against common attack vectors and eliminating OTP phishing risks.

• Prelude SNA fallback: If SNA can’t apply, the user is automatically redirected to SMS OTP or third-party apps like WhatsApp, ensuring smooth onboarding.

Why Businesses Should Care

Traditional verification methods — SMS OTPs or app-based authentication — have served businesses for years, but both bring challenges: delivery delays, fraud exposure, and user friction. SNA addresses these issues head-on.

Benefits of SNA

• Improved conversion rates: No manual code entry reduces drop-offs.

• Enhanced security: Protection against SIM swap and phishing attacks.

• Lower support costs: Fewer tickets related to missing or delayed OTPs.

• Regulatory alignment: Meets MFA requirements in regulated industries.

• Cost efficiency: SNA has the potential to be more affordable than SMS. Consistent with our mission, we work market by market to achieve the best possible pricing, and in active countries we’ve secured rates below SMS.
  
  

SNA in Context: Comparison with OTP Methods

Implementation: How SNA Works

The flow for implementing Silent Network Authentication is straightforward:

1. User submits phone number via your application.

2. Verification request is sent to the authentication service, specifying silent verification as the preferred method.

3. Carrier validation: The network checks the SIM, device, and number ownership.

4. Silent confirmation: If the carrier supports SNA, verification succeeds instantly and invisibly.

5. Fallback: If SNA is not supported or fails (e.g., weak coverage, unsupported carrier), the flow reverts to OTP delivery (SMS or third party app like WhatsApp).

   
   

Prelude Leads the Way in Silent Network Authentication

Silent Network Authentication (SNA) has become a buzzword across the industry. Everyone is talking about it, but very few companies truly make it available as an authentication feature. Most remain focused on selling traditional SMS.

At Prelude, we take a different approach. By combining SNA with our Preferred Channel feature, we are pioneering real adoption of this technology and making sure it works seamlessly within onboarding flows. Our vision is to deliver the perfect onboarding experience by offering as many secure and frictionless verification options as possible, SNA included.

To make this possible, Prelude extends the power of SNA with its Silent Verification feature set:

• SDK integration: Simple setup within iOS and Android apps.

• Automatic orchestration: Prelude chooses the optimal verification method (silent, SMS, WhatsApp).

• Fallback logic built in: Guarantees reliability where SNA is not supported.

• Security-first design: SOC 2 compliance and fraud detection baked into the pipeline.

Prelude SNA will allow us to build the most effective onboarding platform, combining affordability with industry-leading conversion rates.

Get Started with Prelude SNA

Prelude SNA is already available in France at €0.025 (compared to the SMS price of €0.03), and we are actively working on expanding to Germany, Spain, and the UK.

With Prelude, your team can begin leveraging SNA today while maintaining reliability through our Preferred Channel fallback feature. The result is a seamless, secure, and scalable verification experience that keeps onboarding smooth and conversions high.

👉 Explore the SNA documentation and start integrating Silent Verification with Prelude.