Japan & Korea Data Roaming SIM Card

Update November 2014: If you are looking to have this card in your hands before you arrive in HK, or want data in Japan or Korea and not stopping by HK, you can purchase it from our partners at Hong Kong SIM Card, and have it delivered to your address outside of HK.

If you’ve been following, I have recently come back from Japan and had a chance to use a data SIM card I recently saw was being promoted at 7-11 stores. Walked into a 7-11 and saw a little sign promoting a data only SIM card for use in Japan and one for Korea. These cards are sold by HK China Unicom and available for $299 HKD at 7-11 or China Unicom stores throughout Hong Kong. You can see the breakdown of the Japan and Korea cards below.

The Japan card was super easy to use, just popped it into my phone when I landed in Japan, changed the APN setting on my Android phone to “3gnet” as instructed and internet was working immediately. Speeds were speedy enough, middle of the range 3G speeds and I was able to view web sites and maps without any issue at all.

Note I also spotted Groupon is selling these cards at a discount of $248 HKD instead of the usual $299. You can search “unicom” on the Groupon page to see if the deal is still on. I didn’t bother buying it from there though since it was last minute and you need to redeem the voucher at a China Unicom store which was too inconvenient for me.

Sign at 7-11
Sign at 7-11


The HK China Unicom Japan card provides 5GB of 3G data over 7 consecutive days. 日本7日3G上網卡. At $299 for the card, this works out to $43 HKD per day. You can even tether to other devices like your notebook/laptop/tablet/etc, and it appears no restrictions on Skype, Youtube, etc. The data service in Japan is provided by SoftBank, one of the largest mobile carriers. You can activate this card in either HK or Japan and is sold as a micro-sim. You’ll need to find some mobile store to cut the card for you if you need a nano size.

In comparison to the prepaid data SIM cards you can get in Japan at around 3,980 yen, the China Unicom card is a good deal if you’re traveling for 7 days or less due to the fast speed and no data type restrictions. Normally in Japan you can purchase the b-mobile 1 GB card which you can use over 14 days with no restrictions on data use, or the unlimited data card over 14 days capped at 300 kpbs speed. The unlimited card doesn’t allow you to VoIP like Skype or stream videos through Youtube. If you don’t use much data and will be inJapan longer than 7 days, the b-mobile cards may be a better choice. These cards can be shipped to you in Japan and can be any size you want.


The South Korea cards offer 1GB of data over 7 days 南韓7日3G上網卡 and are available in micro-sim too. $299 for this card as well, which is also on-par with the offers in South Korea. Similar feature to the Japan card, 3G data and data sharing tethering to other devices. As a bonus you’ll also get unlimited WiFi service during those 7 days, but I’m not sure how widespread the WiFi coverage is. It says in Seoul you should look for “Olleg WiFiZone” network name. This service is provided by KTF Korea Telecom Freetel.

I think the HK China Unicom Korea card is a good deal for stays of 7 days or less. It offers more data than the local card you can buy in Korea. For example, the STelecom card offers only 500MB or 1GB for 30,000 or 35,000 won, respectively. Howver, on the plus side the STelecom card offers voice calling if you need that. The expiry is 30 days, so better for long days and low data usage. Details can be found here.

SIM card is cut for both regular and micro-SIM sizes. I popped out the micro-SIM card already here.
SIM card is cut for both regular and micro-SIM sizes. I popped out the micro-SIM card already here.


Leave a Reply

  • We didn’t even need a (local) sim card when my sis and I were in Seoul 3 years ago! Free wifi everywhere; public transport, hostel/hotel, restaurants etc. Just make sure you disable the Roaming option.

    Not sure how safe it is to use public/free wifi but we had no problems with our European phones. However, I guess if you travel outside Seoul you might want to get the simcards mentioned in the blog to be on the safe side.

Follow Us

Visit Us On FacebookVisit Us On TwitterVisit Us On InstagramVisit Us On YoutubeVisit Us On LinkedinCheck Our Feed