I have mailed almost all of my money orders to credit card companies because I think there are more PITA things that can happen, although unlikely, by making too many bank deposits of money orders. That having been said, Capital One was by far the slowest to process money orders of AMEX, Barclays, US Bank, Citi and Capital One. Most credit card companies state in their terms and conditions to make one payment per envelope. I was told by Barclays when I called that if more than one payment is in an envelope that it is sent to a human for special processing. So there is a good chance your remaining money orders will clear. I do not know where you are getting your money orders, but if you do not want to incur the stamp costs of doing multiple envelopes, another option is to do check free bill pay at the locations where you buy your money orders. That unfortunately no longer works with AMEX but it does work with Capital One Visa or MasterCard. You just make your payments to a Visa or MasterCard and it is usually $1.88 for a $1,998.12 payment with four swipes of $500 debit cards.