Income tax expense is the amount of expense that a business recognizes in an accounting period for the government tax related to its taxable profit. The amount of income tax expense recognized is unlikely to exactly match the standard income tax percentage that is applied to business income, since there are a number of differences between the reportable amount of income under the GAAP or IFRS frameworks and the reportable amount of income allowed under the applicable government tax code. For example, many companies use straight-line depreciation to calculate the depreciation reported in their financial statements, but employ accelerated depreciation to derive their taxable profit; the result is a taxable income figure that is lower than the reported income figure. Some corporations put so much effort into delaying or avoiding taxes that their income tax expense is nearly zero, despite reporting large profits.
The calculation of income tax expense can be so complicated that this task is outsourced to a tax expert. If so, a company usually records an approximate tax expense on a monthly basis that is based on a historical percentage, which is adjusted on a quarterly or longer basis by the tax expert.