Your typical ACH transfer takes 3 days, but it seems like some banks have set up some kind of agreement or system by which transfers are pretty instant. Between

Your typical ACH transfer takes 3 days, but it seems like some banks have set up some kind of agreement or system by which transfers are pretty instant. Between the bank where I have my personal checking and the bank where my sister and I share an account, transfer is instant. There's a newish means of logging into one bank through another, and once you establish that relationship it enables this kind of transfer.