Mobile suica cards are not refundable so load your money wisely. We start with 2000 yen( per my bank it was USD$13.36 the time we loaded) before we left the States. Since we have world wide phone plan, we just add extra whenever needed. For example- Haneda airport to Shinjuku station is 1400 yen each person, so we add another 2000 yen on my husband’s card. Within Tokyo, subway usually cost 178 yen, so you can estimate how many trips you are going to take. Of course, there are so many places accept CC payment so you can utilize that as well. When out of Tokyo, suica cards are still good for transportation, food and convenience stores, but if you visit some small restaurants or food vendors, cash is the only way. The remaining balance are good for five years, so if you still have funds left, when transfer in Japan, you can use it at the airport. We ended with a little bit over 400 yen each card. Of course you can use the final balance at stores and pay the short payment by cash or other means so that’s another way to drain the funds. You’ll know how easy it is to use mobile suica card in Japan when you arrive. Enjoy your time in Japan!