Transport cards can be purchased in convenience stores and refilled both there and in subway stations at ticket machines. Cards can come empty or with an initial balance and both can be refilled up to a few hundred thousand won. Here is a smaller privately owned store near an apartment complex. The sign hanging from the roof is a promotion for T Money and the purple sign on the right states they sell and refill transport cards.

The entrance next to several ATMs at a bank also states that transport cards can be refilled (충전, 充電, chungjeon) at the ATMs. The sign also mentions refunds (환불, 還拂, hwanbul) are possible here, but does not specify at the ATM or inside the bank branch.

Here is a display of transport cards sold in a convenience store behind the counter.

If you are inside a subway station, you will be able to get a single-use ticket at a machine and refill an existing transport card, but will not be able to purchase one at these machines. Here are two versions of machines found in subway stations in Seoul. These are frequently located near the paid area of stations and sometimes a machine is located just within the paid area for individuals who don’t have enough value in their card and need to add a little cash before they can exit. If you want to see the images and words more clearly, click the picture to see a larger version of the image.

Both types are touch screens and offer support in Korean, English, Japanese, and Chinese. If refilling a card, simply placing your card on the reader will also start the process. If you want to see the images and words more clearly, click the picture to see a larger version of the image.

Here is a similar machine in Daejeon. As opposed to the ones shown above, this is embedded into a wall. If you want to see the images and words more clearly, click the picture to see a larger version of the image.

Here is a close-up of the screen, which has options that do not exist on the Seoul machines. They also display the next three trains in each direction and the first and last trains of the day. If you want to see the images and words more clearly, click the picture to see a larger version of the image.