2-way SMS

2-way SMS service – a combination of MT and MO services, allowing the CLIENT to transmit messages and receive replies from the End User.

The service is provided through a virtual number, issued by the provider. Depending on the destination country, virtual numbers can be presented by long codes, short codes or standard phone numbers.


  1. Short code : 114, 4565,.. (usually up to 5-6 digits)
  2. Long code : 0133-xxxx-xxx (Korea) (special virtual number, does not look like a real phone number; issued by designated entity in each country)
  3. Standard phone number : 7-914-xxx-xx-xx, 82-10-xxxx-xxxx (in some countries Mobile carriers provide numbers similar to standard mobile numbers)

2-way service is widely used for various purposes:

  • Advertisement opt-out (unsubscribing)
  • Customer care lines (*with TOLL-free numbers)
  • Polls and surveys
  • Marketing campaigns



SureM 2-way SMS service flow


Sending SMS to South Korea

  • Guarantee the highest success rate for the traffic sending to Korea
    • (1)We have accumulated full NPDB of three mobile operators for 17 years of experience
      • In Korea, there is Number Portability service provided by main three operators
      • E.g. 010-1234-5678 number, originally belonging to KT can switch to another operator (SKT or LGU+)
      • Fast transmission to the connected operator based on all NPDB information
        (NPDB : Number Portability data base)
    • (2)Supporting messages receipt without blocking from the SPAM policy
      • On 2014, Offered Guideline about transmission of advertising message
      • On 2015, the policy has been revised for filtering SPAM (Enforced on October 2015)
        • ·Policy enforcement to prohibit changing sender ID randomly
        • ·Service implementation to block sending message with stolen number
      • =>We provide a guideline to the customer to send a message which is fitted in the government policy
      • <In case of sending SMS with unavailable sender id or
        sender id which is not match to the numbering plan in Korea >[Failure of Detailed rules] [Proper examples]
    • (3)Possible to send to the minor operators
      • Transmission to the phones connected with KT Powertel , Ann Phone and Internet Phone
      • Numbering system according to the kind of service
        • ·SKT, KT, LGU+ : +82 – 10 – XXXX – YYYY
        • ·Internet phone : +82 – 70 – XXXX – YYYY
        • ·Seoul Landline/ Internet phone : +82 – 2 – XXXX – YYYY
        • ·Other destinations Landline / Internet phones : +82 – 31 – XXX – YYYY
          • ※Other destinations: Gyeonggi (31), Incheon (32), Gangwon (33) and Chungnam (41), Daejeon (42),
            Chungbuk (43), Sejong (44), Busan (51), Ulsan (52), Daegu (53), Gyeongbuk (54), Gyeongnam (55),
            Jeonnam (61), Gwangju (62), Jeonbuk (63) and Jeju (64)
        • ·KT Powertel : +82 – 13 – XXXX
    • (4)Tracing the reason of failed message and issuing weekly report for increasing success rate
      • Delivery rate improvement 70% -> 96%
        • ·The actual successful delivery rate is considered as 100%
          because the failed message of 4% is caused by the reasons below.
        • ·The reason of Failure : Invalid phone numbers or handset power off
      • Delivery rate improvement grounds (failure cause analysis and response)
        • ·Sender ID regulations compliance guide
        • ·Solution for Number Theft Protection Service
        • ·Error code status for non-existent numbers
        • ·Special solution for multilingual messages that are delivered incorrectly
  • Supporting to send messages in multi-language and higher quality service only in Korea
    • (1)All languages supported
      • You may send messages in English, Japanese, Chinese etc.
      • Full multilingual coverage (send messages in any language to any country of the world).
      • [Other company] [SureM]
      • [Other company] [SureM]
      • [Other company] [SureM]
    • (2)Unlike any other A2P providers, we can deliver 140 byte SMS to Korean handsets!
    • (3)Individual 1:1 Customer Management service (with designated Account Manager)
      • Your personal Account Manager is always ready to assist on any possible enquiries and provide the information on successfully transmitted, non-transmitted messages, delivery rate and total indicators in a report, based real-time monitoring system and provide consultations based on the data.
    • (4)Weekly reports
      • Transmission details, delivery rate information provided


Mobile Number Portability (MNP) is a service that allows you to switch over to another mobile service provider while retaining your existing mobile phone number.

Mobile number portability is implemented in different ways across the globe. The International and European standard is for a customer wishing to port his/her number to contact the new network (recipient), which then sends the number portability request (NPR) to the current network (donor). This is known as “recipient-led” porting. The UK and India are the only exceptions to implement the donor-led system. The customer wishing to port his/her number is required to contact the donor to obtain a code (Porting Authorisation Code (PAC) in the UK and Unique Porting Code (UPC) in India) which is then given to the recipient network. The recipient continues the porting process by contacting the donor with porting code. This form of porting is known as “donor-led” and has been criticised by some industry analysts as being inefficient, though prevents MNP scams. It has also been observed that it may act as a customer deterrent as well as allowing the donor an opportunity of “winning back” the customer.


South Korea introduced MNP more than 10 years ago, in 2004.

To know if your country has the MNP implemented, the easiest way to check is ask your mobile providers. MNP gives mobile carriers a good opportunity to lurk in more customers, as retaining one’s mobile number while switching to a better option of service is indeed very attractive.

Here are some of the websites you may use to know about different countries’ policies on MNP:



Sender ID

What is Sender ID?g14110

When you receive a message, what is the first thing you are looking at? The number it came from. It will happen unconsciously, as the text message and its meaning might differ depending on who you received ot.

About Sender ID

– Sender ID is the originated address of which the message comes from.- It is often the displayed sender on the mobile number.- Each country has its own sender ID restrictions

Sender ID can be

  • 1. Alpha sender – Ex. SureM
  • 2. Numeric sender – Ex. 8215884640
  • 3. Alphanumeric sender ID – Ex. SureM123

Here are some examples of Sender ID regulations per country :

    • 1. Korea
      • No alpha / alphanumeric sender ID allowed
      • Only numeric sender ID is allowed
      • Between 0 ~ 12 digits
    • 2. India
      • Need to pre-register alpha Sender ID
      • Fixed 6 digits
      • Ex. SUREMC
    • 3. China
      • Numeric only
      • Need to pre-register signature to be added at the bottom of the message

Ex ) Good day! Thank you using SureM Service. 【SureM】

Every country has different regulations regarding the Sender ID policy. To get a detailed consultation contact SureM.

E-mail : sureminternational@gmail.com


SureM FAQ : What is OPT-OUT? What does [Web발신] mean?

Be it something basic like SMS length or definition of the “OPT-OUT” – in messaging business there are always questions to ask. At SureM, we are constantly working on collecting and updating the data on everything, from technical terms and definitions to latest SMS regulations updates.


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Feel free to pop in to check our some of the questions you might be interested in and email us at sureminternational@gmail.com to ask any that are not on FAQ.

Sending SMS to Korea

There are three major Mobile Carriers in South Korea : Korea Telecom, SKT and LG U+. These days, following the progress in 4G/5G… development, more and more people rely on various messengers rather than SMS. That is for personal communication.

When it comes to corporate use, SMS is still a very important tool in reaching out to the customers, be it advertisement messages or registration codes for some app or service.

When sending SMS to South Korea, there are certain specifics you should be aware of :

  1.  When sending SMS from abroad, the message length is limited to 90 bytes.그림1
  2. Messages beyond 90 bytes will be delivered in one piece, but not as commonly known concatenated SMS (concat, C-SMS). In Korea, there is a term of LMS (Long Message Service) for messages of 91~2000 bytes.
  3. One of the special headers might be added :
  • [Web발신] (“Sent from Web”), indicating that the message was sent via A2P route.
  • [국외발신] (“Sent from abroad”), indicating that the route used does not belong to a local provider
  • (광고) (“Advertisement”), indicating that message contains promotional information.

IMPORTANT! The first 2 headers are automatically added by the Mobile Carriers and are not counted in the overall byte count. Thus, if you are charged by your provider for adding these extra bytes… Well, let’s say you have a good reason to find a new one!

E-mail : sureminternational@gmail.com