Skatteunderlag

Skatteunderlag is a term used in tax law to describe the total amount of income, wealth, and other quantities that are subject to taxation in a given jurisdiction. It functions as the basis for calculating tax obligations and is defined by national rules, including allowable deductions, exemptions, and adjustments. The exact scope of the skatteunderlag can differ between taxes and between countries.

In practice, skatteunderlag can include personal income (such as wages and business income), capital income (interest, dividends, and gains), and net wealth, as well as property values for property-related taxes. Depending on the system, certain items may be included or excluded, and specific allowances or credits may reduce the base on which tax is assessed. Some taxes use separate bases for different tax types, such as income tax, wealth tax, or social contributions.

The calculation process typically involves aggregating all taxable amounts, applying applicable deductions and exemptions, and then applying the relevant tax rates or tax credits to determine the final tax payable. Tax rates may be progressive, flat, or a combination, and the skatteunderlag can be adjusted by policy changes, indexation, or annual revaluations.

Skatteunderlag is central to tax administration and compliance. Tax authorities rely on it to compute tax bills and to monitor accuracy, while taxpayers and accountants use it to prepare returns and plan financial decisions. Changes to the tax base can have broad implications for revenue, equity, and economic behavior.