Americans were more generous last year than the year before, giving nearly $300 billion to charity in 2011, according to a new report from the Center on Philanthropy at Indiana University.

But not all those donations are going where they’re intended. A recent study from Stamp Out Poverty — an aid advocacy group — estimates that charities in Britain lose almost $50 million a year thanks to problems with exchanging currency. Things are no doubt worse in the United States, whose charitable market is six times bigger.