FAQs and answers about Flash SMS

What is a Flash SMS and how can you use it?

Many SMS gateway providers offer them: Flash SMS. Maybe you are also asking yourself the question: what is a Flash SMS and should I use it for my business? Don’t worry, you are not alone in this. In this blog post, we’ll explain what Flash SMS are, where exactly the difference is to regular SMS, in which cases you can use Flash SMS and when you’re better off using regular SMS. Let’s get started!

What is a Flash SMS?

A Flash SMS is a special type of SMS that is displayed to recipients differently than regular SMS. It is also known as class 0 SMS. Flash SMS are (usually) displayed directly in the recipient’s screen. Thus, they do not have to be opened by the recipient and therefore attract extra attention. Moreover, they are not stored on the receiving device. Unlike push messages, however, they do not disappear from the recipient’s screen until the recipient actively closes the message. Flash SMS can contain more than 160 characters, but the message is cut off after a certain length. We therefore recommend that you do not send more than 160 characters. In our tests, up to 200 characters were possible in most displays.

On some devices Flash SMS  may arrive be received like regular SMS and are also saved like that. Others do not show Flash SMS on the lock screen.

What is a Flash SMS and how are they different to normal SMS?

What is a Flash SMS and how is it different from a regular SMS? Click to enlarge.

Which use cases are Flash SMS suitable for?

Due to their special features, Flash SMS are particularly well suited for some use cases, but less so for others. As with regular SMS, make sure your recipients know what to expect so they can trust your messages.

  • Warnings and alarms

    A message that attracts as much attention as Flash SMS is, of course, often used for alerts. Here it is important that your recipients know how to handle the message, as they will not be able to view it again after closing it.

  • One-time passwords

    Flash SMS are also popular for sending one-time passwords, especially in the course of two-factor authentication. This makes sense, among other reasons, because Flash SMS are not stored on the receiving devices.

  • Updates during events

    During events, you can easily keep your employees informed of important changes. From admission stops to finding lost people to end-of-shift information, your messages will reach their destination quickly.

  • Alerting emergency teams

    When a response option is not necessary, Flash SMS can also be used to alert emergency personnel. Again, it is important that your team knows how Flash SMS work so that they retain all the important information.

In most cases, Flash SMS are not suitable for sending marketing SMS. On the one hand, advertising messages in Flash SMS seem intrusive, because your customers can no longer decide for themselves whether they want to read your message right now or not. On the other hand, your customers cannot return to the message if they are interested in your offer later.
In addition, smishing awareness may cause your recipients to distrust Flash SMS if they contain promotional messages, especially if the sender ID cannot be displayed.

Good to know

On most newer receiving devices, sender IDs for Flash SMS are no longer displayed. Instead, they are replaced by a generic sender name.

I want to send Flash SMS in my company! What do I have to do?

Flash SMS cannot be sent from most cell phones and using Flash SMS apps is not wise, as you will never know what exactly you are sending, via which platform or provider and who may read your messages. However, with a flexible SMS provider like seven.io you can easily send Flash SMS to employees or customers and also integrate this sending into your software. All you need is an account with us and enough credit to send the Flash SMS.

You can send Flash SMS from our webapp as well as via our API. Also many integrations support sending. You can find detailed information about sending Flash SMS in our helpdesk article.

What is your use case?

Are you using Flash SMS for a special project? We are always happy to hear about your experiences. Feel free to drop us a line.

All the best
Your sms77 team

Header picture by Azat Satlykov via Unsplash

Edit on 5.8.22: The original version said that Flash SMS could contain 160 characters. In fact, you can use more characters, but the message is terminated in the display after a certain number of characters. We made changes to reflect this.

There was also a note in the original about problems receiving Flash SMS on iPhones. We have adapted the note and the content of the corresponding link, since similar phenomena now also occur on Android devices.

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