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What is a flash call?

A flash call is an authentication method for verifying identity without requiring any specific action from the end-user. It is a relatively new technique for implementing two-factor authentication (2FA). When a user initiates a 2FA process, a flash call is triggered to deliver the activation code. Unlike traditional methods that require the user to manually input a code or respond to a prompt, a flash call is automatically initiated to the end-user's phone. As mentioned above, the main benefit is that the end-user doesn't need to answer the call or take any additional steps. The mere receipt of the call is sufficient for the system to authenticate the user, creating an almost seamless process.

How does flash call work?

Typically, when the phone application triggers an activation code, it enters a "monitoring state," awaiting a call. The voice call received has a specific Caller Line Identification (CLI) where the last 4-6 digits serve as the required activation code. In most cases, the app can automatically recognize the code and the flash call appears in the phone log as a regular missed call, requiring no manual intervention.

This approach is more user-friendly and cost-effective than alternative authentication methods. As the market started to see widespread A2P SMS price increases, flash calls emerged as an appealing alternative, offering a budget-friendly option for both enterprises and service providers when used transparently.

However, for Mobile Network Operators (MNOs), this shift marks a decline in revenue since many are unable to identify and monetize it effectively.

Is flash call considered fraud?

Flash call monetization solution

Flash calling demonstrates how advances in network technology driven by cost reduction and service enhancement can enable new forms of communication. However, there is always a caveat; in this case a threat to the integrity of the authentication process itself since it is performed without active consent. Additionally, MNOs suffer a direct fall in revenue.

And herein lies a fundamental dilemma, is flash calling really fraudulent? Flash calling is indeed a new and innovative way of remotely authenticating end-users - in most cases seamlessly. This begs the question, could flash calls eventually become the preferred choice of end user authentication and just how far would that impact the MNO? 

Currently, the biggest challenge is that flash calls are essentially a bypass method, where an aggregator intentionally switches from SMS 2FA to flash calls without end-user consent. 

The only way to address this is to recognize flash calls as a legitimate means of delivering authentication codes, and only if they are being used transparently by the service provider with full end-user consent. As long as flash calls are being used as a bypass authentication method, MNOs will continue to see revenue erosion (especially for A2P SMS revenues) and the only step forward is to proactively address and monetize this new approach.

The first step of flash call monetization and control is successful detection with a high level of accuracy and a low false-positive rate.

Arelion's flash call solution ensures 99,995% accuracy in flash call and fraud detection. As a Tier-1 international voice carrier, connected to major flash call service providers and MNOs, we are strategically positioned for a comprehensive overview of the service flow, and can seamlessly identify and track flash calls at source.

Once the Arelion service is implemented, MNOs are afforded full control of the following: 

Flash call monetization

After implementation of a dedicated trunk independent of existing international voice trunks, MNOs can enable flash call termination and bill per call session/attempt. 

Flash call blocking

Incoming flash calls can be blocked and redirected through alternative authentication channels, such as SMS. This can leverage an immediate increase in SMS A2P (Application to Person) traffic.

Arelion’s flash call monetization service and the benefits for MNOs

Arelion's flash call monetization service provides several advantages for MNOs - enhancing control, flexibility, visibility, protection, and transparency. These include:

Revenue control

Arelion's solution equips MNOs with the necessary tools to effectively monetize flash calls and boost SMS A2P volumes, providing MNOs with enhanced revenue control and a strategic advantage. 


MNOs get to decide their own destiny, by maintaining full control of the monetization process. The flexibility of Arelion's solution allows MNOs to tailor their approach in accordance with evolving needs and market dynamics. 

Wholesale visibility and control

In functioning as an extension of an MNO's network, Arelion grants wholesale visibility and control. This bridges the MNO-service provider gap, increasing proximity to the subscriber. It establishes a seamless connection for better operational efficiency overall. 

Full protection

Arelion's flash call service can integrate seamlessly with SMS firewalls, for comprehensive protection. This ensures that MNO networks are strengthened against potential threats, providing a more secure environment for both flash calls and SMS transactions. 


Arelion maintains a transparent and collaborative partnership with MNOs. Operators benefit from full data access and control, for increased transparency in their operations and decision-making. 

In essence, Arelion's flash call monetization solution empowers MNOs with a suite of tools and capabilities that not only optimize revenue streams, but also enhance operational control and security. Through our collaborative approach, we can nurture a straightforward yet dynamic relationship with our partners. 

For more details about Arelion’s solutions, contact our sales and solution experts.

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