If you require a currency exchange service once at your destination you might be able to save some money if you hold off with your exchange until you reach the hotel instead of exchanging at the airport.
In the current case, I just needed a small amount of extra HKD and decided to exchange 20 Canadian Dollar instead of using the ATM for a small transaction like this and found my hotel offered decent rates.
Especially in Hong Kong, one should absolutely avoid to exchange money at the Travelex Exchange counters which are prevalent at the airport. John wrote about this two years ago already (see here) and since then the situation has not improved. The rates Travelex rates are just ridiculous as ever before.
Usually I get cash with my VISA card that offers free withdrawals worldwide, but since I still had some HKD, I decided to just exchange some cash. I always carry a couple hundred Dollar/Euro in cash just in case ATM’s don’t work or for other situations where quick cash is helpful. Even though transactions with my VISA are free of charge, there are sometimes ATM transaction charges that are not covered by the bank, so sometimes it’s better to exchange small amounts in cash.
As I was staying at the Hyatt Regency in Hong Kong, I figured their rates might be alright and I was correct. The hotel was offering 113.40 HKD for 20 CAD cash which is close to what XE displayed for Interbank rates.
Not all hotels offer such favorable rates so you should really compare with an app like the XE which I use frequently.
Some airports are notorious for having horrible exchange rates at their exchange booths while others are quite ok. Beijing, Hong Kong and Sydney have been really bad in terms of either bad rates or a high commission fee for the exchange and I’d never recommend to do any transactions there if you can avoid it. All the banks at Bangkok and Tokyo-Narita/Haneda airport have offered decent rates.
Travelex is consistently one of the worst service providers in this regard. They also have a counter at Shinjuku Station in Tokyo which is a rip off as well. You should try and exchange money at your hotel that has a vested interest in not making the customer feel totally ripped off after already spending money on a hotel room which is their main business.