What is a major requirement for depreciation under IFRS that is not required under US GAAP?

Under IFRS, one major requirement is the concept of component depreciation, which necessitates the allocation of the cost of a tangible asset to its significant components when those components have different useful lives. This approach recognizes that various parts of an asset may wear out at different rates and hence should be depreciated separately to reflect their usage accurately. This method ensures financial statements provide a more accurate representation of an entity's asset base and the associated depreciation expense over time.

In contrast, US GAAP does not mandate component depreciation, allowing entities to depreciate assets as a single unit, regardless of the differing useful lives of asset components. This can lead to less precise expense recognition concerning the actual wear and tear of the various parts of an asset.

The other options, such as straight-line and accelerated depreciation methods, are both acceptable under both IFRS and US GAAP. The revaluation method is permissible under IFRS but not a requirement that distinguishes it from US GAAP, where assets are typically held at historical cost without a revaluation model. Therefore, component depreciation best exemplifies a significant difference in the treatment of depreciation between the two accounting frameworks.