What is FIFO, LIFO, and FEFO?

FIFO, LIFO and FEFO are rules for which stock leaves first. FIFO (first in, first out): oldest stock ships first — the default for most physical businesses, keeps goods from aging on shelves, and matches how accountants usually value inventory. LIFO (last in, first out): newest stock ships first — rare physically, mostly a US accounting method for tax treatment (not permitted under IFRS). FEFO (first expired, first out): stock closest to its expiry date ships first — the correct rule whenever products carry dates (food, cosmetics, supplements, pharma), because a newer-but-shorter-dated batch should leave before an older-but-longer-dated one.

Operationally: pick FIFO unless you have expiry dates, in which case FEFO — and note FEFO requires batch/lot tracking with dates, which is a software feature, not a shelf-arrangement trick.