Vanguard required me to change my Prime Money Market Fund to a Vanguard Cash Reserve Money Market Fund. As a result, unknown to me, there are no check writing options in the Cash Reserve Fund and my Prime checks are no longer honored. I found this out after I put a deposit on a car and the Prime check was not not accepted. To Vanguards credit they did send me a message just in time today as I was going to pick up the car tomorrow a 100 miles away. I, of course, quickly called the dealer to try to explain why the check bounced. I have not bounced a check in 50 years! I did call Vanguard and was told that Vanguard did nor have checking on the cash fund they required me to move my funds from my Prime account. Because of the time I had to pay $10 to have an electronic transfer to have the funds in my local bank by tomorrow. If I bounced a check for the full amount I would no longer be your customer. Not sure what I will do now.