Guidelines

South Korea (KR)

We've compiled regulatory and compliance information to help ensure you're communicating effectively and compliantly around the world.

Locale Summary

Locale name

South Korea

ISO code
The International Organization for Standardization two character representation for the given locale.

KR

Region

Asia

Mobile country code
A three digit code associated with the given locale and used in conjunction with a Mobile Network Code to uniquely identify mobile networks.

450

Dialing code
The dialing prefix used to establish a call or send an SMS from one locale to the given locale.

+82

Guidelines

Two-way SMS supported
Whether Twilio supports two-way SMS in the given locale.

No

Number portability available
Whether number portability is available in the given locale.

Yes

Twilio concatenated message support
Concatenation refers to the capability of splitting a message that is too long to be sent in one SMS into smaller pieces and then joining the pieces at the receiving end so that the receiver sees the message as one. 

Long messages are no longer supported and will be delivered and displayed on the handset as multiple separate segments.

Message length
How many characters can be sent given a particular message encoding before the message will be split into concatenated segments.

One SMS segment can contain up to 140 bytes. This is equivalent to either 140 characters using the GSM 8-bit unpacked (commonly known as ASCII) encoding or 70 characters using the UCS2 16-bit encoding.

Twilio MMS support
Multimedia Messaging Service (MMS) provides a standards-based means to send pictures and video to mobile phones.

Converted to SMS with embedded URL

Sending SMS to landline numbers
How Twilio handles an SMS message destined for landline telephone number.

You cannot send SMS to a landline destination number: the Twilio REST API will throw a 400 response with error code 21614, the message will not appear in the logs, and the account will not be charged.

Compliance considerations
Twilio strongly encourages customers to review proposed use cases with qualified legal counsel to make sure that they comply with all applicable laws. This table lists some general best practices.

SMS messages toward South Korea would be automatically appended with [Web 발신] which means the message is A2P or [국제발신] which means the message is sent from abroad. Only numeric senderId is supported and it would be automatically prefixed with 009 or 006. Only EUC-KR characters are supported by the South Korean mobile operators so carefully review your content and only use characters that are on the list. Sending of adult and gambling related content is strictly prohibited. 

Message delivery to M2M numbers is on best-effort basis only.

Twilio strongly encourages customers to review proposed use cases with qualified legal counsel to make sure that they comply with all applicable laws. The following are some general best practices:

  1. Get opt-in consent from each end user before sending any communication to them, particular for marketing or other non-essential communications.
  2. Only communicate during an end user's daytime hours unless it is urgent.
  3. SMS campaigns should support HELP/STOP messages, and similar messages, in the end user's local language.
  4. Do not contact end users on do-not-call or do-not-disturb registries.

Phone Numbers & Sender ID

Alphanumeric
 

Pre-registration

Dynamic

Operator network capability
Whether mobile operators in the given country support the feature.

Not Supported

Not Supported

Twilio supported
Whether Twilio supports the feature for the given country.

---

---

Sender ID preserved
In some countries sender IDs for certain sender types are not preserved and are changed for compliance and/or deliverability reasons. In these countries mobile subscribers will see a different ‘from sender ID’ than the one sent by you.

---

---

Provisioning time
Provisioning is the process of getting the sender ID approved and registered with mobile networks (depending on country requirements). Provisioning time is how long this process takes in the given country.

N/A

N/A

UCS-2 support

N/A

N/A

Use case restrictions

N/A

N/A

Best practices

N/A

N/A

Long codes and short codes
 

Long code domestic

Long code international

Short code

Operator network capability
Whether mobile operators in the given country support the feature.

Supported

Supported

Not Supported

Twilio supported
Whether Twilio supports the feature for the given country.

Not Supported

Supported

---

Sender ID preserved
In some countries sender IDs for certain sender types are not preserved and are changed for compliance and/or deliverability reasons. In these countries mobile subscribers will see a different ‘from sender ID’ than the one sent by you.

---

No

---

Provisioning time
Provisioning is the process of getting the sender ID approved and registered with mobile networks (depending on country requirements). Provisioning time is how long this process takes in the given country.

N/A

N/A

N/A

UCS-2 support

N/A

Supported

N/A

Use case restrictions

N/A

N/A

N/A

Best practices

N/A

Please take note that international longcode would be appended with 009 or 006 as regulation by the mobile operators

N/A


For the benefit of all our customers, these guidelines are provided to help you comply with applicable requirements and to help ensure Twilio's platform remains compliant with global telecommunications ecosystem requirements. These guidelines represent our current understanding of common compliance requirements generally applicable to Twilio and its customers, and do not constitute legal advice. By posting these guidelines, Twilio makes no assurances regarding the legal compliance of your application built using our APIs. You are expected to understand and abide by all compliance obligations applicable to your specific application. You should check these pages regularly for updates as telecommunications ecosystem requirements continue to evolve and change, and the information below may be updated or changed without notice.