oh come on, at least learn how to type your prospective employer's name right; it is PwC and not PWC.

such tiny matters are frown upon.

anyway, i have not interned in PwC before, but i would suggest that you tuck a classic looking (nothing fancy) tie into your pocket.

so if you observe majority of the peeps there, are with ties, just excuse yourself quickly to the nearest lavatory, and put it on.

good luck for your internship programme!

have fun!