Korea (South)

Basics
The Republic of Korea (= South Korea) has 3 mobile network operators: supplemented by many MVNOs on the three networks.
 * SK Telecom
 * kt olleh (by Korea Telecom)
 * LG U+

LG U+ doesn't have any prepaid plans, so will be only briefly mentioned.

South Korea can still be a tricky country to buy a local SIM card. There never have been any 2G/GSM networks and some legal regulations still impede the use of a local SIM card like in many other countries. That's why some WiFi and "WiBro" operators and rental agencies are listed at bottom of the list as an alternative.

Also, it's unlikely you will have any luck with CDMA service as phones are rarely sold outside Korea and very few other countries (like the US). The only real options for visitors are 3G/UMTS on 2100 MHz or 4G/LTE phones. If you are travelling from North America make sure your phone supports 2100 MHz on 3G as many US phones only support 850 or 1900 MHz.

SIM cards of the major providers are sold in the operators' stores, SIMs of the MVNOs rather in convenience stores like CU, 7-Eleven and GS25 like in airports.

Frequencies
The 2G network of KT based on CDMA has been switched off in 2012, while SK Telecom and LG U+ maintains their CDMA networks (switch-off schedules not announced). There is a very good coverage on 3G up to HSPA+ speed with SK Telecom and KT on 2100 MHz and on 4G/LTE with all operators added by many WI-Fi hotspots in the country. Following table contains frequencies on both standards CDMA and GSM used by each carriers:

1 Primary LTE frequency.

Frequencies in italics are CDMA-only and not compatible with usual GSM devices.

SK Telecom and KT both work on 3G and 4G/LTE in the cities on frequencies used all over Asia, Australia and Europe. Forget about using CDMA with a foreign device: SK Telecom requires a lengthy process even for Koreans while LG U+ uses the 1800 MHz band as only carrier in the world for CDMA. Both carriers now sell own branded phones without CDMA. So you can expect good coverage with a GSM phone on any carrier. You may still use CDMA roaming, if your phone/operator supports it (e.g. Sprint or Verizon devices from the US). Remember, 2G-only GSM phones as well as pre-OS10 BlackBerrys without 3G support don't work in S. Korea. On the other hand, if your device supports 4G, this country will have the best 4G coverage at almost 100%. Furthermore, Korea has an excellent network of open and commercial WiFis and networks based on Mobile WIMAX technology, they call WiBro. 5G is scheduled to start in 2018 as one of the first countries.

Regulations
Not so long ago South Korea had severe legal restrictions in place which hampered your internet access if you were not aware of them. Up to 2012 it used to run a whitelist scheme of accepting only certain certified devices to their networks based on their IMEI numbers and no foreign phones could be used in the country on a local SIM card without official approval. Until 2015 you were allowed to buy a SIM card at arrival in the country, but immigration law mandated that your personal data needs to be entered into the system first which could take up to 3 working days. 

Luckily things have changed now for the better and you can buy a SIM card like in any other country. Since 2015 all foreigners visiting Korea can open a mobile prepaid account on the day they arrive in the country as authorities have improved the foreigner identification system. Nowadays, you still have to send a request to add your device to the network. This is done at the point of purchase. It can take 20 to 60 minutes before your connection will be activated. That's why you should choose a designated device for your SIM card and tether from it instead of changing the SIM from one device to the other.

Market for visitors
The most accessible network for foreigners is kt olleh by Korea Telecom. SK Telekom is only slowly opening up and LG U+ remains closed due their market policy and frequences. Kt olleh SIM cards can most easily be purchased in their "global stores" where staff speaks some English or at the airport. So offers can also be bought or ordered before your arrival online sent to you or to be picked up in the country. Some smaller resellers of kt olleh and rental companies complete the picture. Finding a SIM card and an English-speaking agent in town, can be a much harder task to do.

kt olleh (by KT - Korea Telecom)
Olleh or KT (Korea Telecom) is the public provider and 2nd network in the country with a good coverage (see above). It's a formerly public enterprise, is relatively cheaper than SK Telecom with the largest WiFi coverage in Korea and a well-organized prepaid plan available.

They have special stores called "global stores" at airports and key city points where they support English-speaking service especially to foreigners. They have the broadest service in the country to foreigners: They sell prepaid SIM cards, do phone rentals with SIM cards, do "egg" rentals (see below) and sell WiFi vouchers for their WiFi hotspots. At Incheon airport, KT has several service desks in the arrivals hall where you are likely to find signs advertising SIM cards (as do the other mobile network operators - SK and LG+).

Most visitors go for the tourist SIM sold at airports or the rental of a device with a SIM card. Their regular olleh Simple prepaid plan is much harder to get and maintain for a foreigner and geared more to long-time visitors.

kt Mmobile tourist SIM (olleh Mmobile)
kt Mmobile by a subsidiary of KT aimed at tourists. It's operating on the 3G and 4G/LTE KT olleh network with speeds up to 100 Mbps.

Availability
Prepaid SIM cards for purchase are available at Korean four major international airports (Incheon, Gimpo, Jeju and Gimhae) in the arrivals section in the convenience stores of CU and 7-Eleven chains.

It's possible to buy it in 7-Eleven stores in Myeong-dong, Hongdae, Dongdaemun, Jongno or Haeundae, but nowhere else. For this reason it's recommended to buy either at the airport or online.

They also allow you to order your SIM card online on their website before arrival and pick it up at certain locations in airports..

Activation
You need to go online and fill in the required personal information. It will be activated in less than 1 hour. However, if you try to activate it outside of their working hours (Mon-Fri: 9am-8pm, weekend and holiday: 10am-8pm), activation process will be completed after 9am on the next working day.

Their plans are not available for Koreans. The activation process contains entry history screening and therefore anyone, who has dual citizenships must use their foreign passport to process activation.

Data price
They don't offer "unlimited data", but provide an usual prepaid SIM service (with calls and SMS, no incoming fees) all valid for 30 days only, no time extension possible: To check remaining data amount, you need to call 080-770-0114 (for free on any phone) /1899-6283 / 070-4906-6283 (customer center).
 * mini, micro nano SIM card with 1 GB: US$ 26.90 online, in CU store at Incheon: ₩ 34,900
 * mini, micro, nano SIM card with 2 GB: US$ 38.90 online, in CU store at Incheon: ₩ 49,900

Recharges
Additional top-ups are available on their website. PayPal and interntl. credit cards are accepted, but some cards may be declined. Data is sold at 500 MB increments for ₩10,000 (US$ 9) up to 2.5 GB. After recharge, you will be notified by a SMS. This top-up may take a day, if you do it outside of business hours.

If you can't top-up online, you can also make a top-up at any local convenience store like 7-Eleven, CU and GS25 nationwide 24/7. In the store you ask the clerk to recharge KT Mmobile prepay, pay desired amount and receive either a direct top-up or a PIN slip. With a 11-digit PIN call 080-013-0114 (for free) and follow the message on the line. Recharge will be finished at the moment and you will receive notification SMS message in real time.

Note that you can't extend the initial 30 days period of the SIM card by another top-up. To use it for longer, you need to buy a new SIM instead. You don't need to return the SIM after use.

kt olleh Mobile Rental and data-only SIM purchase
The same olleh stores airport stores also rent SIM cards, smartphones and WiFi routers too at their airport branches and flagship stores called "Global stores". Available phone types are iPhone5, Galaxy Note1(SHV-E160), Galaxy R Style (SHV-E170K). You should make a pre-order online, if you want to be sure to get a certain device. They also sell data-only SIMs with the same data price.

SIM card rental and purchase
They sell a data-only prepaid SIM and rent out a general prepaid SIM with voice and data. Both SIMs include "unrestricted" data use during the rental period at a max. of 5 Mbps. For rent you need to link your credit card and in case of loss ₩ 10,000 will be charged. Remember, you need to give or sent back their voice SIM. Rates for both SIM cards are:
 * for 5 days: ₩ 27,500
 * for 10 days: ₩ 38,500
 * for 30 days: ₩ 71,500

Smartphone and WiFi router rentals
They rent out different smartphones with SIM cards to use rightaway. The rental fees for phones or WiFi routers are: Data is an expensive ₩ 1.5 per 0.5 KB. But you can book unlimited data on 3G and 4G for 5,000 won per day. Speed is limited to 5 Mbps.
 * 1-10 days: ₩ 3,000 per day
 * 11-20 days: ₩ 2,000 per day
 * 21-30 days: ₩ 1,000 per day
 * over 30 days: free

Furthermore, they rent out "eggs". These are Mifi routers to build a local hotsport running on WiMAX (or LTE) technology. The rental fee is the the same as for smartphones with the same data pack. Be prepared to pay around ₩ 200,000 deposit for the rental or have it blocked on your credit card.

Availability
KT's regular prepaid product (olleh 선불) can be loaded with data packs from 4,000 to 50,000 won called olleh SIMple at all of their stores. Each top-up amount involves a validity period. Purchase and booking of packages is easiest in their global stores (list of locations). However, note that this SIM can't be purchased at Incheon International Airport, but there are other SIMs you can get on the KT network at the airport (see below). If you are unable to visit a global store, then their English-speaking hotline can act as a translator for you. Also, as of February 3, 2017 prepaid SIM cards are sold only between 10am and 6pm on business days only despite that stores works longer. Same restriction applies to recharging SIM cards with cash in "Global Stores" (if you have a Korean bank card, you can also recharge on Saturday from 10am to 6pm), see below for the option of recharging in convenience stores.

You have to buy the prepaid card itself and it comes without any credit. Default data rate is 0.28 won per 0.5 KB. It's on 3G/HSPA+ and/or 4G/LTE. If you have a smartphone that supports the LTE bands that KT olleh supports (essential is band 3 on 1800 MHz) then you can sign up for "olleh simple LTE". The SIM card costs 5,500 won for 3G (Olleh simple) or 8,800 won for 4G (olleh simple LTE). Nano SIM cards are available only with the 4G option.

One thing to keep in mind is SIM card validity, currently they are offering a plan with minimum 180 days validity (no shorter periods on first time purchase) fro 30000 won. However, you can extend the validity an en existing SIM card for shorter durations than 180 days. So for first time visitors staying in Korea for a month, you will spend 30 000 won for validity + 8800 won for the SIM card + data pack charges (another 8800 won for 500 MB on 4G).

Data feature packages
These monthly packages called can be booked on the card (for 3G HSPA+) link: These monthly packages called LTE SIMple can be booked on the card (for 4G/LTE) link: Please note that LTE prepaid data rate is cheaper than 3G prepaid data rate. So sign up for LTE data, which will fall back to 3G HSPA+, if your phone does not support LTE bands.
 * 100 MB: 5,500 won
 * 300 MB: 8,800 won
 * 500 MB: 11,000 won
 * 1 GB: 16,500 won
 * 2 GB: 22,500 won
 * 4 GB: 38,500 won
 * 500 MB: 8,800 won
 * 1 GB: 14,300 won
 * 2 GB: 19,800 won

Also note that you must have some (greater than 0) amount of credit on your card, or else your data package will not work (and customer service may not know why!).

Olleh's extensive WI-FI network (see below) is added unlimited for free on the packages of 300 MB or more. You will need to connect to the secure olleh Wi-Fi network. It will ask you for authentication - choose SIM authentication.

kt olleh WiFi voucher
Olleh runs the biggest WiFi network with more than 100,000 WiFis in the country, which is a very good alternative to mobile internet in the cities, but quite limited on the countryside (http://zone.wifi.olleh.com/#none). You can buy codes at many 7-Eleven, By the Way, GS25 or Mini Stop stores :
 * 1 hour: 1,100 won

A detailed guide how to log on in English is given here: http://first.wifi.olleh.com/en/aboutService.html
 * 24 hours: 3,300 won

Technical Settings (for all kt olleh products)
Many phones pick up the correct carrier settings automatically. If internet doesn't work properly, these additional manual settings are required:
 * APN: alwayson.ktfwing.com MCC: 450 MNC: 08
 * Server / MMSC: http://mmsc.ktfwing.com:9082

More info (for the different sections)

 * about the olleh MMobile tourist SIM in English: http://krsim.net/
 * about olleh Mobile Rental in English: http://roaming.kt.com/rental/eng/product/phone.asp
 * about olleh prepaid SIM plans in Korean only: http://product.olleh.com/wDic/index.do?CateCode=6719
 * about olleh WiFi zone in English: http://first.wifi.olleh.com/en/index_new.html

EG SIM
EG (for Evergreen) is a MVNO on the olleh / KT network with good coverage on 3G-only and aimed mostly to visitors and tourists. They have English-speaking staff in their outlets and offer pick-up locations and delivery too. Have in mind for this extra service EG is more expensive than buying a SIM directly from KT Olleh.

Availability
This provider lets you order your SIM card online already for pick-up or delivery prior to arrival. You can order it online on their website either to be picked up at certain locations like train stations or airports, or to be sent to hotels or even abroad. They have many collection places like the international taxi booth or hotel information booth at Seoul (Incheon) International Airport, whose staff speaks English: (pick up locations). Delivery for additional 2,000 KRW to any place in Korea and for 17,000-20,000 KRW to some countries in Asia and Australia. These monthly plans are offered (nano SIMs are 5,000 KRW more):

The official distributor www.egsimcard.com offers delivery to about 50 countries worldwide.. SIM cards are sold at € 9.95 for micro and € 10.95 for nano SIM plus € 3.50 for shipping and handling at these monthly rates: The SIM card is also available at these offline locations in S.Korea (map). When you arrive at the airport early or late, you can’t collect EG SIM card at collection places, but you will have to buy it at specific selling points directly. These offline cards are sold for a surcharge summing up to 30,000-50,000 KRW (with less credit, because sellers charge an "activation fee"), and still need to be activated.
 * 500 MB: 11,000 KRW
 * 1 GB: 16,500 KRW
 * 2 GB: 22,000 KRW
 * 5 GB: 44,000 KRW

Activation
This is only necessary for offline bought cards. For this you need to go on the website here and fill in some data. Activation can only be done at business hours Monday to Friday and when you are in the country for more than three working days already. Wi-Fi needs to be activated separately (see below).

Data charges
Default data is 55.8 KRW per MB, WiFi is not available. You can add these monthly data packages (tax incl.): Also available for delivery or pick-up in Korea are the following monthly data/credit/SIM bundles (for standard & micro SIMs - add 5,000 won for a nano SIM):

WiFi
The packages include unlimited free olleh/KT WiFi, which has the biggest network especially in the cities: WiFi map. Passes for Wi-Fi only can be obtained separately (see KT olleh article).

Once you activate your SIM card in your phone, the WiFi registration is usually automatic. In cases when this doesn't work, you have to give your device details information, so that they will register you. For this you need to know your IMEI number and WiFi Mac Address, which you can find in your device settings. Log on or sign in your account at their website, go my account, check phone number and device specs, and click register. Registrations can only done Mon-Fri 9am-10pm and Sat/Sun 9am-6pm.

Recharges
To recharge you need to register on their website too. You can use any international Visa, Mastercard, JCB, AmEx credit or debit card. They say, that top-up cards are sold at 7-Eleven, C Space, GS 25 and Mini Stop, but many users had problems finding them. So better use a credit card instead. SIM cards have a 30-days validity. To extend SIM live, get it at their head office in downtown Seoul (map) or go there with a SIM bought at other places to get longer validity.

Technical Settings
Many phones like iPhones will pick up the correct carrier settings automatically. For credit check, internet booking and top-up you can download the EG SIM Android App. Its also possible to use the app for top-up with PayPal.
 * APN: alwayson.ktfwing.com
 * MCC: 450
 * MNC: 08
 * Server / MMSC: http://mmsc.ktfwing.com:9082

More information

 * Website in English: https://roaming.kt.com/rental/eng/main.asp

NeoKOSIM and Link Korea
NeoKOSIM is a start-up company that has recently launched a partnership with KT to offer a 4G/LTE unlimited data access prepaid SIM card for travelers coming to Korea. The same service is offered as Link Korea.

Data-only pass
You can order online on their website and will receive a PDF voucher via your e-mail after payment. SIMs can be picked up at main gateway airports in Korea (Incheon, Gimpo, Gimhae, Jeju) and their Hongdae Office in downtown Seoul. These SIMs are for purchase and not to be returned. Tethering is possible, no calls or texts, but VoIP. Max. speed is 5 Mbps.

Voice & data pass
You can order online on their website and will receive a PDF voucher via your e-mail and will pay when you pick up the SIM'''. '''They can be picked up at Incheon airport, at the Olleh KT roaming center (gate 6) inside in the arrival hall 1F. These SIMs are for rental and are to be returned:

The allowances are for data only. Voice and text consumptions will be billed extra. As a deposit you'll need to to provide a credit card or pay 100,000 KRW which is given back when you return the SIM. If you don't return it, you shall be charged additionally for all of your calls and text messages to your given credit card.

Both product lines are sold/rented for the same rates:
 * 5-day pass for 27,500 KRW  (~ US$ 25, tax incl.)
 * 10-day pass for 38,500 KRW (~ US$ 34, tax incl.)
 * 30-day pass for 71,500 KRW (~ US$ 64, tax incl.)

Annex Korea SIM
To be picked up in their office in Seoul only, they offer another SIM with unlimited domestic text and voice and 12 GB data, beyond throttled to 3 Kbps. A 15 day pass is sold for US$ 45, 30 days for US$ 72. This SIM is for sale and not extendable, VoIP is not possible.

Link Korea
Link Korea has an identical offer to NeokoSIM. You'll need to book online on this pageat least 2 days before your arrival to Korea. They will contact you through email to get personal information and arrival date for registration. You can receive confirm email. they will send you a detailed pick-up guide. Pick-up your SIM card at one of their pick-up points in Incheon Airport. Required deposit: by credit card open or in cash (100,000 KRW or 100 US$). Pick-up point at gate 6 Olleh Roaming Service Desk has 24 hours business hours. Enjoy mobile communication during your trip. Return it after use: Upon the return of the SIM card, the usage fee for calling and texting is calculated and paid by credit card or in Korean Won only. If a SIM card is not returned in time, a fee for the loss of the card (of 10,000 KRW) and the usage fee will be deducted from the paid deposit. The duration of rental can be extended by calling the service center.

More info

 * APN: lte.ktfwing.com Server/MMSC: http://mmsc.ktfwing.com:9082 MCC : 45 MNC : 08
 * Website for NeokoSIM: http://www.neokosim.com


 * Website for Link Korea: http://www.linkkorea.co.kr/sim/k-sim/

SK Telecom
SK Telecom is the biggest mobile provider in South Korea. It's more geared to contract customers, has good membership benefits, a good customer service and is generally more expensive than Olleh. SK Telecom has recently added a prepaid plan for short term tourists. Like KT, SK also has counters at Incheon airport where SIM cards can be rented too.

SK operates 3G on the usual 2100 MHz, but 4G/LTE on the rather unusual 850 MHz (band 5) as primary frequency that is rarely covered by devices from overseas (except those capable of AT&T's LTE in the US). The more usual 1800 MHz (band 3) is only employed for back-up.

PPS (for prepaid service) plan is designed for a foreign travelers to take advantage of its SK telecom network. Plans support 3G and 4G/LTE as long as you have a device capable of unusual band 5 (850 Mhz) for LTE. PPS prepaid SIMs can be subscribed only in the SKT Roaming Center at Incheon International Airport (located between gate 6 and 7) at business hours from 8am to 6pm.

PPS Plan: All-in-One Plan
The All-in-One plan allows for calling and texting but you need to choose a base plan. The cheapest is PPS Lite for 166 won per day. More expensive plans only lower the voice rates. On top upon activation you have to load a minimum balance of 10,000 won giving the SIM a validity of 60 days. Top-up vouchers are available in denominations of between 5000 and 50,000 won each extending the validity of the phone number between 30 days or up to 1 year. The phone number remains valid for another 10 days after expiration of the credit.

For their All-in-One Plan the following data loads can be added, all with a maximum validity of one year or the expiry of the SIM, whichever comes sooner. The data allowance is maintained as a separate account; you cannot convert the call credit into data allowances.
 * 100 MB: 2,000 won
 * 500 MB: 10,000 won
 * 1 GB : 15,000 won
 * 2 GB: 19,000 won
 * 5 GB: 33,000 won

PPS-Plan: Data-only Plan
If you want data-only you can opt for activating this plan, there is no daily base-charge or a base plan:

SK Telink - 7mobile
SK Telink is their usual consumer brand. But prepaid services are only offered by its MVNO 7mobile. Their prepaid plan T-Money has a base charge of 202 won per day and these monthly data packages to be added: For 110 won per day, access to WIFI of T-Zone (http://www.twifi.co.kr/view/index.jsp) can be added.
 * 100 MB: 5,000 won
 * 500 MB: 10,000 won
 * 1 GB: 20,000 won
 * 2 GB: 40,000 won

SK Telecom prepaid SIM for travellers from Hong Kong Airport
5 day or 8 day SIM cards are being offered by Klook Travel Technologies for pick-up at Hong Kong airport for travellers who may be travelling from Hong Kong or transiting through the HKG airport. These cards must be pre-ordered and then picked up at HKG International Airport on this website.
 * 2.8 GB (at 4G speeds) for 5 days: 20,086 won / HK$ 128
 * 5 GB (at 3G speeds) for 8 days: 23,225 won / HK$ 148

SK Telecom Roaming
Similar to olleh roaming, SK Telecom rents out smartphones and MIFI routers. Unlike olleh they focus more on the internet than some special stores to foreigners. The rentals can be booked online through here.

A smartphone rental is for 3,000 won per day and 6,000 won/day for 3G data up to 1 GB (overuse: 5 won per 0.5 KB) or unlimited WIFI for 2,000 won/day on T-Zone WIFI (see above). Discount is given to online reservations, long time rentals and returning costumers. Deposits are 300,000-700,000 for the devices.

The MiFi is given out for 3,000 won per day and for 5,000 won/day you get unlimited data on 3G and LTE.

More information

 * APN: web.sktelecom.com
 * Website for SK Telecom Roaming and PPS plans in English: https://www.skroaming.com/main.asp
 * Website for SK Telink 7mobile in Korean: https://www.sk7mobile.com

Mobile Pop (WiFi Plaza Korea, formerly S Roaming)
Mobile Pop a.k.a. WiFi Plaza Korea was formerly called S Roaming and has now relauched. The similarity with SK roaming has probably led to conflicts. They rent out devices on the LG U+ network (see Basics) which uses CDMA for 3G and 4G/LTE. Generally, it has not such a good coverage on the countryside as the two major networks, but is fine in the cities too.

They don't rent SIM cards anymore. Instead they rent out pocket WiFis for 3G and 4G.

WiFi rental
Their 3G/WiFi router is for US$ 7.49 per day, their 4G/LTE router for US$ 9.49 per day plus 10% taxes. For service, they sell two packages with data: You need to give a 200,000 won deposit. Their rental offices are conveniently located at:
 * 500 MB and 7,290 won airtime: 30,000 won + 10% taxes
 * 1 GB and unlimited airtime: 35,000 won + 10% taxes
 * Airport Gimpo: Terminal 3F (opened on weekdays between 7am and 4pm)
 * Airport Incheon: between gate 7 and 8 (opened between 6am and 10 pm)

More information

 * http://mobilepop.co.kr/main/index.php in English

The Arrival Store
The Arrival Store provides SIM card and phone rentals in South Korea on a daily or monthly basis. They can be ordered online to be collected at Incheon Airport or to be sent to any postal address in Korea.

For short-term travelers they offer SIM cards with unlimited calling, text and data (within S. Korea) for US$5 per day plus a once-off US$15 SIM card fee.

For longer term contracts they offer different rate plans for 3, 12, or 24 month rental contracts on SIM-only plans that can be seen here. Contracts operate on the KT olleh's LTE/4G network and provide unlimited access to this operator's hotspots throughout Korea too.
 * Website: www.thearrivalstore.com