Most PhD students receive some sort of stipend during their tenure at the university. My question is, how is the stipend distributed in most universities? Is it in a lump-sum form (i.e 23000 per year given just like that) or is it on a monthly/quarterly basis?

MRC (and probably most research councils) pay it quarterly in advance i.e. if you start on 1st Oct, you should get 3 months' worth of stipend on that date.

That is, of course, dependent on how well organised your departmental admin/university finance people are! I have known people stipdendless for several weeks while unknown processes were going on behind the scenes. :-(

AHRC send it quarterly in advance, to the universities, who are then responsible for distributing it to the award holders. My university does this by bank transfer through the banking system, which takes a bit of setting up at the start of funding, but worked well afterwards.

I get mine quarterly as I get paid directly from the research council. However, other people I work with get theirs monthly as they are paid from the institute doctoral training account.

I get mine from the uni and it gets paid monthly :-)