> For the complete documentation index, see [llms.txt](https://docs.hackle.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.hackle.io/en/crm-marketing/sms/getting-started.md).

# Getting Started with Text Messages

{% stepper %}
{% step %}
**Personal Data Processing Agreement**

Hackle will collect and use mobile phone numbers, which are the personal information of the client's users. According to the Personal Information Protection Act, message sending is possible only after completing the following steps.

1. Execute a personal data processing agreement between the client and Hackle. If there is an internal personal data processing agreement form, use it; otherwise, use Hackle's form.
2. Add text to the client's Privacy Policy > Personal Data Entrustment section indicating that personal data processing is entrusted to Hackle. Example text: Recipient - Hackle Co., Ltd. / Purpose - Sending customized CRM campaigns based on user behavior and data analytics / Retention Period - Until contract termination
   {% endstep %}

{% step %}
**Pre-registration of Sender Number**

When using the text service, you must register and use your own sender number. If a sender number is falsely displayed and transmitted, the service for that number may be suspended.

* [Register Sender Number](https://dashboard.hackle.io/config/platform-integrations?tab=TEXT_MESSAGE)
  {% endstep %}

{% step %}
**Register 080 Opt-out Service**

If you are sending Promotional Messages via text, you must include a free opt-out method using the 080 opt-out service, allowing recipients to opt out or withdraw their consent free of charge.

#### FAQ

{% hint style="info" %}
**Q. Do I have to use the 080 number issued by Hackle?**

A. No. You can use an 080 opt-out number issued by another vendor for sending Text Messages or Brand Messages.

However, there are two things to be aware of. First, depending on your existing vendor, it may not be possible to use it at all. Second, opted-out recipients are not automatically synchronized with the Hackle system. Therefore, you must manage the opt-out list yourself, and you must also separately handle excluding these recipients from your campaign send targets.

For these reasons, we recommend issuing your 080 number through Hackle. After reviewing the notes above, if you would like to use an external 080 opt-out number, please contact the Hackle team separately.
{% endhint %}

{% hint style="info" %}
**Q. Do I have to use a number starting with '080'?**

A. Yes. Currently, only '080' numbers are supported as opt-out numbers.
{% endhint %}

* [Apply for 080 Opt-out Number](https://dashboard.hackle.io/config/platform-integrations?tab=SETTING)
  {% endstep %}

{% step %}
**Credit Top-up**

A separate sending cost is incurred when sending text messages. You can top up credits to send text messages.\
For details, see the [Message Pricing](/en/crm-marketing/message-price.md) document.
{% endstep %}

{% step %}
**Phone Number Collection**

Since text messages are sent based on the recipient's phone number, user phone number collection is required.\
For details, see the [Phone Number Collection](/en/crm-marketing/crm-properties/collect-phone-number.md) document.
{% endstep %}

{% step %}
All preliminary preparations are now complete. Start your text message campaign now!
{% endstep %}
{% endstepper %}


---

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