Generally, the smaller the AGI, the greater the percentage of deductibility of itemized deductions. California uses the federal standard for deductibility of property taxes on state income tax. Usually, the main benefit is a tax shield resulted from tax deductibility of interest payments. Permanent differences result when deductibility rules differ in perpetuity between accounting and tax law. In high tax countries the deductibility of interest expenses is perceived to be most valuable. Canada&colon; there is no general rule on the deductibility or non-deductibility of kickbacks and bribes. The platform also called for mortgage interest deductibility. Additionally, corporations with zero-emissions automobiles have a deductibility rate of 120 percent. The classification is quite significant in terms of the deductibility. The deductibility of the other items in Publication 502 was never in dispute.