I can understand not wanting to maintain the currency data. But it does mean that a key element in transactions will come from a source over which you have no control and which is not liable for mistakes.

Possibly the data gets miskeyed on the web service at the point you are taking your snapshot of exchange rates and your user gets some unusual results.

Perhaps your system should at least confirm the new download rates and source and time with the user before implementing them.

Its an area thats interesting. We spend a lot of time validating data input. Data coming from a web based service should also be subject to that validation.


Nick Mason