dpulavarthi
Good questions. I believe that we'll find out more about this when we receive our Oxford packages in the mail. I'm sure they'll contain the Financial Guarantee Form, and other information.
As far as the deposit is concerned, I'm pretty sure we can pay by card or by electronic transfer on the Oxford website.
On the "proof of funds" front, I think Oxford is more interested in whether or not we have the means to procure the full funding, and not whether we have all of the cash on hand. Take a look at the following webpage:
https://www.ox.ac.uk/feesandfunding/prospectivegrad/As a U.S. citizen, I'm quite lucky, in that I can fill out a FAFSA, and Oxford's Cost of Attendance Excel worksheet, and borrow any amount I cannot cover with my own savings from the US government. I do not know how many people on this forum are in the same boat, but I thought I'd put it out there.
Anyway - navigating the link above and taking a look at the package Oxford is going to send us should answer a lot of the questions we may all have.