"papers, paperwork," 1889, British schoolboy slang, originally "toilet-paper," from bum-fodder; see bum (n.1) + fodder.
Entries linking to bumf
bum n.1
"buttocks," late 14c., "probably onomatopœic, to be compared with other words of similar sound and with the general sense of 'protuberance, swelling.' " [OED]
fodder n.
Old English fodder "food," especially "hay, straw, or other bulk food for cattle," from Proto-Germanic *fodram (source also of Old Norse foðr, Middle Dutch voeder, Old High German fuotar, German Futter), from PIE *pa-trom, suffixed form of root *pa- "to feed."