Taxation of leases that are not long funding leases: finance lessees: general issues: change in depreciation rate under generally accepted accounting practice
If, during the term of a lease, there is a change in the rate at which a leased asset is depreciated and the revised view of the life of the asset can be justified, then the allocation of the rentals from the year of change onwards should reflect the revision. Thus, if under GAAP the depreciation charge is increased, the rentals allocated to the periods affected will also be increased.
Exceptionally, the assets may have retained their value (or even increased in value). Where this is the case the change of view will cause a reduction in the annual depreciation charge going forward.