> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hypersender.com/llms.txt
> Use this file to discover all available pages before exploring further.

# SMS OTP Guide

> How to send OTP codes over SMS with a lower risk of carrier filtering or dropped messages.

Some carriers may drop OTP SMS messages, especially when the message is too clear, too repetitive, or looks like a standard verification template.

We tested this with Egyptian carriers and verified that this can happen. The same issue may also appear with other carriers.

<Warning>
  Delivery is never guaranteed. Even if a message format works on one carrier, the user still needs to test and verify it with their own destination numbers and regions.
</Warning>

## Keep the OTP message short

For OTP SMS, shorter and less explicit wording may work better than a clear verification sentence.

For example, this message may be dropped by some carriers:

```text theme={null}
Your verification code is: 12736. This code will expire in 5 minutes.
```

Instead, try a shorter format like:

```text theme={null}
login {app_name} 12345
```

This style may work better because it is shorter and less obviously formatted as a verification template.

## Recommendations

* Keep the message very short.
* Avoid long explanatory OTP sentences when possible.
* Avoid adding unnecessary punctuation or repeated template wording.
* Test the exact content with the carriers your users actually use.
* Verify delivery across different countries and operators before relying on one format.

## Important note

The format `login {app_name} 12345` is not a guarantee. It is only a practical pattern that may perform better in some cases, so every user should test and verify it in their own environment.