Frank26 

If you are ever audited and you have your receipt, you’ll probably be in the 20% range.  You got a million bucks, you give Uncle Sam $200,000 of it.  But if you don’t have a receipt, I’m sorry, you’re going to be in the 40% range. You had a million bucks, give Uncle Sam $400,000 of it…That’s why you need a receipt…Nobody needs a receipt when you go to the bank to exchange.  They just want the currency.  On top of that they’re going to tell you if that currency is real or not.  They’ll run it though their accounting machines. : Frank26