--- title: "Flash Call: Secure authentication via incoming call" description: "Flash call: secure authentication via incoming call. Use one-time access for registration, two-factor authentication, and purchases" image: https://qsrtele.com/hubfs/qazar-website/images/default-images/qazar-feature-image.jpg --- - Products ### Channels of communication - [SMS - Notification](https://qsrtele.com/products/sms?hsLang=en) - [Viber Business](https://qsrtele.com/products/viber-business?hsLang=en) - [WhatsApp Business API](https://qsrtele.com/products/whatsapp-business-api?hsLang=en) - [Push](https://qsrtele.com/products/push-notifications?hsLang=en) - [Email](https://qsrtele.com/products/email?hsLang=en) - [Telegram](https://qsrtele.com/products/telegram?hsLang=en) ### Verification Services - [Flash Call](https://qsrtele.com/products/flash-call) - [HLR](https://qsrtele.com/products/hlr?hsLang=en) - [Mobile marketing](https://qsrtele.com/products/mobile-marketing?hsLang=en) ### Targeted mailings - [CPA](https://qsrtele.com/products/cpa?hsLang=en) - Solutions ### Solutions - [Security Protect your customers and their personal information with strong authentication solutions.](https://qsrtele.com/solutions/security?hsLang=en) - [Client Support Competent and proper identification of customer needs is the foundation of a long relationship and excellent service.](https://qsrtele.com/solutions/client-support?hsLang=en) - [Process Efficiency We can help improve workflow efficiency by communicating with your customers in a single platform.](https://qsrtele.com/solutions/process-efficiency?hsLang=en) ### For business - [Retail and e-commerce Turn casual subscribers into loyal customers](https://qsrtele.com/business/retail-and-e-commerce?hsLang=en) - [Banks and Financial Sector Deliver a superior digital customer experience across the most popular channels.](https://qsrtele.com/business/banks-and-financial-sector?hsLang=en) - [Healthcare Allow your patients to choose their own convenient communication tool.](https://qsrtele.com/business/healthcare?hsLang=en) - [FMCG Meet customer demand and expectations as you expand into new markets.](https://qsrtele.com/business/fmcg?hsLang=en) - [Documentation](https://qsrtele.com/ru/dokumentaciya?hsLang=en) - [For partners](https://qsrtele.com/for-partners?hsLang=en) - [Support](https://qsrtele.com/contact-us?hsLang=en) - [About Us](https://qsrtele.com/ru/o-nas?hsLang=en) - Eng - [Russian](https://qsrtele.com/ru/produkty/flash-call?hsLang=ru) - [Spanish](https://qsrtele.com/es/productos/llamada-flash?hsLang=es) - [German](https://qsrtele.com/de/produkte/flash-call?hsLang=de) Products Channels of communication - [SMS - Notification](https://qsrtele.com/products/sms?hsLang=en) - [Viber Business](https://qsrtele.com/products/viber-business?hsLang=en) - [WhatsApp Business API](https://qsrtele.com/products/whatsapp-business-api?hsLang=en) - [Push](https://qsrtele.com/products/push-notifications?hsLang=en) - [Email](https://qsrtele.com/products/email?hsLang=en) - [Telegram](https://qsrtele.com/products/telegram?hsLang=en) Verification Services - [Flash Call](https://qsrtele.com/products/flash-call) - [HLR](https://qsrtele.com/products/hlr?hsLang=en) - [Mobile marketing](https://qsrtele.com/products/mobile-marketing?hsLang=en) Targeted mailings - [CPA](https://qsrtele.com/products/cpa?hsLang=en) Solutions Solutions - [Security](https://qsrtele.com/solutions/security?hsLang=en) - [Client Support](https://qsrtele.com/solutions/client-support?hsLang=en) - [Process Efficiency](https://qsrtele.com/solutions/process-efficiency?hsLang=en) For business - [Retail and e-commerce](https://qsrtele.com/business/retail-and-e-commerce?hsLang=en) - [Banks and Financial Sector](https://qsrtele.com/business/banks-and-financial-sector?hsLang=en) - [Healthcare](https://qsrtele.com/business/healthcare?hsLang=en) - [FMCG](https://qsrtele.com/business/fmcg?hsLang=en) [Documentation](https://qsrtele.com/ru/dokumentaciya?hsLang=en) [For partners](https://qsrtele.com/for-partners?hsLang=en) [Support](https://qsrtele.com/contact-us?hsLang=en) [About Us](https://qsrtele.com/ru/o-nas?hsLang=en) # Flash Call ## Number verification technology via incoming call. - Deliver codes and data to customers with cutting-edge authentication technology via a call. - The code will be announced by voice or you will be asked to enter the last 4 digits of the number. [Consult an expert](https://qsrtele.com/contact-us?hsLang=en) ![hero-flash-calls](https://qsrtele.com/hubfs/qazar-website/images/hero-flash-calls.webp) ## Why should you choose Flash Call ![class](https://qsrtele.com/hubfs/qazar-website/images/class.webp) ### Why is Flash Call service so popular? The cost of an incoming call is many times cheaper than traditional SMS, while the quality of service is not inferior neither in speed nor in security to classic SMS and push service. Our API provides the ability to integrate with various applications and on any device, and the cost per call allows you to significantly save your budget. Flash Call is currently the least expensive and easiest way to authenticate for your customers. ![puzzle-hand](https://qsrtele.com/hubfs/qazar-website/images/puzzle-hand.webp) ### How Flash Call works - To confirm an action in the app or on the website, the system asks for the user's phone number. - The user enters their phone number and then receives an incoming call, where the last 4 digits will be the authorization code. - The user enters the code and confirms the action in the app or on the website. ![flash-calls](https://qsrtele.com/hubfs/qazar-website/images/flash-calls.webp) ### Advantages of the service - ##### High level of security Only the owner has access to the mobile phone - ##### Immediate confirmation Authorization is available almost immediately. No need to waste time waiting for it. - ##### Service reliability API is based on proven technologies. You are always welcome to consult our experts - ##### The service is maximally modernized Can be used on different platforms and in different applications - ##### Price/efficiency ratio The cost is lower than that of sending SMS. ##### Products - [SMS - Notification](https://qsrtele.com/products/sms?hsLang=en) - [Viber Business](https://qsrtele.com/products/viber-business?hsLang=en) - [WhatsApp Business API](https://qsrtele.com/products/whatsapp-business-api?hsLang=en) - [PUSH](https://qsrtele.com/products/push-notifications?hsLang=en) - [Email](https://qsrtele.com/products/email?hsLang=en) - [Telegram](https://qsrtele.com/products/telegram?hsLang=en) - [Flash Call](https://qsrtele.com/products/flash-call) - [HLR](https://qsrtele.com/products/hlr?hsLang=en) - [Mobile Marketing](https://qsrtele.com/products/mobile-marketing?hsLang=en) - [CPA - Lead generation](https://qsrtele.com/products/cpa?hsLang=en) ##### Solutions - [Security](https://qsrtele.com/solutions/security?hsLang=en) - [Process efficiency](https://qsrtele.com/solutions/process-efficiency?hsLang=en) - [Client Support](https://qsrtele.com/solutions/client-support?hsLang=en) - [Retail and e-commerce](https://qsrtele.com/business/retail-and-e-commerce?hsLang=en) - [Banks & Financial Sector](https://qsrtele.com/business/banks-and-financial-sector?hsLang=en) - [FMCG](https://qsrtele.com/business/fmcg?hsLang=en) - [Healthcare](https://qsrtele.com/business/healthcare?hsLang=en) ##### Documentation - [API Documentation](https://qsrtele.com/ru/dokumentaciya?hsLang=en) ##### Company - [About Us](https://qsrtele.com/ru/o-nas?hsLang=en) - [For partners](https://qsrtele.com/ru/dlya-partnyorov?hsLang=en) - [Contact Us](https://qsrtele.com/ru/svyazhites-s-nami?hsLang=en) 2026 Quasar © All rights reserved