Balance appears whenever you make a purchase. Users can also check their last 10 transactions at the following places:
At Octopus Enquiry Machines at MTR stations
By requesting a printout at an MTR Customer Service Centre and 7-Eleven or Circle-K outlet (a HK$3 fee will be charged by these service providers.)
Using a PCCW eye device
Using an Octopus PC Reader

Your Octopus can be reloaded up to HK$1,000 in total value at thousands of locations throughout Hong Kong by cash. You can reload at the following places:
Authorized Add Value Service Providers, such as convenience stores, supermarkets, fast-food chains.
Any Customer Service Centres of MTR, Airport Express Line and Light Rail.
KMB Customer Service Centre at the Sha Tin Central Bus Terminus
New World First Ferry Octopus Service Centres at the piers on Cheung Chau, Mui Wo and Peng Chau and at Central piers 5 and 6
New World First Bus Customer Service Centre at the Admiralty (East) Bus Terminus
Citybus Customer Service Centre at the Central Exchange Square Bus Terminus
You can also top up using Add Value Machines at MTR and selected Light Rail Stations.
What's more, you can reload your Octopus by electronic fund transfer at selected ATMs of the AEON ATM network (applicable to AEON Credit Card holders only).

For On-Loan Octopus (both Standard and Personalized Octopus), you can go to any MTR Customer Service Centre to apply for a refund of your remaining value.

You can turn in the card at the airport and get a refund. You and your wife need separate cards and they can be purchased at the airport express station in the airport.