Korea - Credit Card acceptance-Seoul

How widely accepted are credit cards in Seoul?
For example, can credit cards be used for:
a) KAL limo bus ICN-Seoul
b) refill T-Money
c) intercity buses
d) most restaurants?
e) tourist sites' admission e.g. palaces, museums
f) taxis

If they are accepted, do merchants tack on a surcharge?

I've never been charged extra when I used a credit card at a restaurant in Korea.

You can use the T-Money card for intercity buses and most taxis(that have the reader). Not sure about the KAL limo bus since I've only taken the regular Airport Limo bus.

It's been a long time since I've gone to a tourist site in mainland Korea but I did use a credit card when I went to Jeju's tourist sites.

Well.... I can't be of too much help, since our only visit there was for a 12 hour layover at ICN last November....

But I do recall that on our whirlwind tour of the city, credit cards seemed to not be accepted as widely as one would expect in Europe or North America (I guess that's not a big surprise.) For example, I'm pretty sure they didn't take them at the Gyeongbokgung Palace... and I want to say that there WERE some machines in the metro that were supposed to take them, but didn't really. I do know that the one sit-down restaurant we visited (for lunch) did take them, but the cafe where we had coffee did not.

I think in general, don't expect ubiquitous acceptance. There are convenient ATMs at ICN outside security, and plenty around the city. I would just grab $75 worth to get started, but then again, I hear I'm lucky to have a bank that doesn't charge fees for foreign ATMs.

a) KAL limo bus ICN-Seoul - No idea.
b) refill T-Money - No
c) intercity buses - No
d) most restaurants? - Yes
e) tourist sites' admission e.g. palaces, museums - Yes
f) taxis - Yes - If it says Card on the roof

There are convenient ATMs at ICN outside security, and plenty around the city. I would just grab $75 worth to get started,

The ones at ICN will be fine, but not all within the city are foreign-card friendly. Maybe 1/5 will accept foreign cards.

The ones at ICN will be fine, but not all within the city are foreign-card friendly. Maybe 1/5 will accept foreign cards.

Good to know. Does the same breakdown apply to English speaking ATM's? And is there a particular bank that does better with accepting foreign Interac cards than others?

Good to know. Does the same breakdown apply to English speaking ATM's? And is there a particular bank that does better with accepting foreign Interac cards than others?

They will all have a English language option, but only ones that have a little 'Global _____' service will accept foreign cards.

Thanks to all who posted.

Just wanted to close this out after having just left Seoul. As noted by others, couldn't use credit card for the airport bus, trains or buses. However was able to use cc for all the taxis I took (widely accepted), restaurants, shows (Cookin' Nanta) and palaces I visited. Used the ATM at ICN once and never needed to get more cash in the city.