This hotel is connected to Ibis which has a 24hrs convenience store (Nice to C U). Via this store, you can purchase / top-up Wow Pass #(for foreigners) or Namane Card. It is also connected to Yongsan Station and a Mall. So, topping up Transport pass (T-pass) is also easy.
Note #: Wow Pass holds 2 functions. 1. It allows you to store money to be used almost everywhere within Korea without carrying cash around. 2) It can be used as T-pass. However, you will need to top up T-pass before using.