Assumptions behind FIFO and LIFO methods

FIFO assumes that the assets that are remaining in inventory are matched to the assets that are most recently purchased or produced. Because of this assumption, there are a number of tax minimization strategies associated with using the FIFO asset-management and valuation method.
LIFO assumes that an entity sells, uses or disposes of its newest inventory first. If an asset is sold for less than it is acquired for, then the difference is considered a capital loss. If an asset is sold for more than it is acquired for, the difference is considered a capital gain. Using the LIFO method to evaluate and manage inventory can be tax advantageous, but it may also increase tax liability