The U.K. 's Payment Council says assessments have been made to figure out how much cash is needed in London during this tourist surge and what denominations will be most useful .
The U.K. 's Payment Council works with banks and other cash providers .
The U.K. 's Payment Council , which works with banks and other cash providers , says assessments have been made to figure out how much cash is needed in London during this tourist surge and what denominations will be most useful .