Flash Call
Authorization via call to the subscriber, where the verification code consists of the last 4 digits of the phone number
Connect
Easy integration
Twice as cheap as SMS
Flash Call Operation Algorithm
Flash Call
Start demonstration
- Enter any phone number (no calls will be received during the demo)
- Click «Start Flash Call»
- The system will display a random caller number
- Enter the last 4 digits of that number
- Enjoy instant authorization!
Advantages of Flash Call
Speed
The call arrives within
5–10 seconds
Convenience
If the client misses the call or forgets the digits, the phone number remains in the missed calls list
Safety
Prevents third parties from intercepting the confirmation code
Cost
Flash Call is cheaper than
sending an SMS code
Where Flash Call is used
During registration on websites or mobile applications when the phone number is used as a login
For obtaining one-time access without registration: downloading files, viewing content, and more
For password recovery or change on websites or mobile applications
In two-factor authentication, when an additional code is required alongside the main password
In services to protect against bots, when the system verifies that it is interacting with a real person
In services to protect against bots, when the system verifies that it is interacting with a real person
Who сan benefit from Flash Call
Online stores
For quick registration, login, and order confirmation
Delivery and logistics services
To verify order details or recipient contact information
Marketplaces
To prevent fake accounts and securely top up wallets in user accounts
Any business using SMS authentication
Flash Call is a more cost-effective and faster alternative to SMS codes
How to connect Flash Call services
1. Request a сonsultation
Contact our team via the feedback form or by phone. We are ready to answer all your questions and help you choose the best solution for your business.
2. Contract signing
After selecting the authorization system, we will prepare and agree on a service agreement with you. This ensures transparency and protects your interests.
3. Technical integration
Our development team will integrate the authorization system into your existing business processes. After integration, we will perform system testing to guarantee its correct operation and compliance with all specified functions.
4. Service launch
After completing all stages and successful testing, the authorization system will be put into operation. You will be able to enjoy all the benefits it provides.
For all business sectors interacting with clients
Each month, 150,000 users log in to the website and app of the client
Every month, 1.2 million users log in to their personal accounts on the website and app
Over 100,000 customers use the Voice Password system monthly
A modern and cost-effective method of two-factor user authentication for websites and apps
The Flash Call service offers a modern and cost-effective method for two-factor user authentication. Instead of the traditional SMS with a code, the user receives a brief phone call, and the last 4 digits of the caller's number serve as the verification code. This approach is significantly faster — the call arrives within 5–10 seconds — and more affordable. It ensures high deliverability and stability because a phone call is one of the most reliable communication channels.
This service is ideal for any business sector that requires quick and secure customer authentication—whether on websites, in mobile apps, or offline sales points. Setup takes just 1–2 business days. Flash Call not only provides substantial cost savings but also enhances security. Moreover, this method improves the user experience by making the authentication process nearly instant and extremely simple for the customer.
Why choose Unibell authentication?
By selecting Unibell's authentication systems, you get a reliable solution that helps your business grow and develop, ensuring security and convenience for your customers
Ease of integration
Our solutions easily integrate into existing systems and platforms. We provide all the necessary tools and documentation so you can seamlessly connect authentication to your project.
High level of security
SMS code interception by third parties is impossible: the call is made from the subscriber’s number and immediately confirms access.
Universal applicability
Suitable for websites and mobile apps: registration, login, password reset, bot protection — all can be implemented via Flash Call.
Support and infrastructure
Reliable cloud platform with technical support — we ensure stability and quality of the service.
Successful
authorization
Frequently asked questions
How long does setup take?
The authentication setup takes just 1–2 business days.
How secure is the Flash Call method?
This method offers a high level of security. The code is not stored in messages and is tied directly to the call itself on your SIM card, making it practically impossible to intercept or steal.
Who is it suitable for?
The Flash Call service is suitable for any business sector that requires customer authorization on websites, in apps, or at offline sales points.