Spectrum fee amortization rules govern instalments, transfer adjustments, and rectification on non-compliance under the income tax regime. Amortization of spectrum fee is allowed in equal instalments over the period for which the spectrum remains in force, beginning from the tax year in which the business commences or the fee is actually paid, whichever is later. On transfer, the remaining unallowed expenditure is adjusted for loss, gain, or full recovery, with special rules for partial transfer and amalgamation or demerger. No depreciation is allowed where amortisation is claimed, and non-compliance permits rectification and recomputation. The term actually paid includes approved upfront and deferred payment arrangements.