Nexmo is using Adaptive Routing in South Korea, through a selection of different high-quality suppliers.
Only numeric Sender IDs are allowed.
Alpha Sender IDs will be automatically replaced with a global numeric sender ID.
Every message content will automatically have either of the following text added:
"[Web 발신]" - it means SMS sent from web
"[국제발신]" - it means SMS sent from aboard
The messages length is 140 bytes (160 characters in GSM-7 or 70 characters in Unicode), including the leading text (see "Message content" section above").
Messages above 140 bytes will be delivered as Long Message Service (LMS) by our local routes. This type of messages supports up to 2000 GSM characters or 1000 Unicode ones. Nexmo will bill those messages in the same way that SMS concatenation works in other destinations.
Illegal content - e.g. Gambling, Adult
Please aware illegal content (especially gambling and adult-related content) is not allowed to all Korean networks.
Korean networks support character encoding EUC-KR, supporting Korean text and some of the traditional Chinese characters. Simplified Chinese characters are not supported.
Binary messages are not supported
Other features/restrictions of note:
Delivery Receipts are provided, however, they are not handset generated and only indicate that the network has received the message.
Virtual Numbers in South Korea:
Virtual Numbers in Korea are only reachable locally. In addition, concatenated SMS is not supported locally, the message will be split into parts.
Inbound messages will be limited to 40 characters if using Unicode (e.g. Korean characters), or 70 characters if using GSM/Latin encoding (e.g. English).
Voice Outbound in South Korea
Local Korean numbers as CLI are forbidden to be used to send traffic towards South Korea.