My husband and I decided to split a vacation condo with another couple. We charged the full cost of the condo on our Costco citibank credit card. The other couple gave us their half in cash. My husband and I were wondering if we were going to have to get a money order or cashiers check to get the cash applied to our credit card. I decided to try the ATM. I was able to put my credit card in the ATM without a PIN - which I don't have. I simply selected payment and inserted the cash into the ATM. The ATM totalled up the cash and asked if I wanted to apply the payment to my credit card. I printed the receipt and away I went. Problem solved.