Flash SMS (sometimes also called Flash Messages) are a special kind of SMS. They are displayed directly on the recipient's screen without the recipient having to open them. Usually, mobile phones can neither save these messages (with exceptions) nor send them themselves. However, there are apps that allow you to send them.

Flash SMS are ideal for emergency notifications, for example. Using this type of SMS to send advertising is not recommended. On the one hand, these kind of messaged are particularly intrusive, and on the other hand, your customers will not be able to revisit the SMS if they did not have the time to look at your offer at the time of receipt. Here, regular SMS are usually the better choice.

If you want to send Flash SMS, you can select the type Flash SMS in the function menu to the right of the input field at the top of the webapp.
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Of course you can also send Flash-SMS via HTTP API and Email2SMS. You can find the respective parameters here:
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​Flash SMS via HTTP API

Flash SMS via Email2SMS

Please note that sender IDs for Flash SMS are no longer displayed on many new devices. Any sender ID set are replaced by these cell phones with neutral names such as "SMS", "Class 0 SMS" or simply "SMS Message".
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This is a reaction of the manufacturers to phishing via SMS. Since Flash SMS messages look like a system message on many devices, this is supposed to prevent consumers from falling for scammers who misuse the sender ID to disguise their message as an official message.

Under certain circumstances Flash SMS can be displayed incorrectly on iPhones: here Flash SMS are received as normal SMS when the screen of the device is locked. Apple is aware of this bug, but has not fixed it yet (as of July 2021). We will make a note here when the normal reception of Flash SMS on locked iPhones is possible again.

Not all Android devices display Flash SMS in the same way. However, it is likely that Android devices do not display Flash SMS in the lock screen. Instead, the message might show as a Flash SMS after unlocking the device or as a regular SMS. We have no influence on the way Flash SMS are displayed.

If your recipients do not receive your Flash SMS, please check the article "SMS has not been received". 


Please also make sure you've read the sections Flash SMS on iPhones and Flash SMS on Android devices.

If you don't find a solution there that works for you, please contact our support.

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