Exemptions are made for social reasons. Taxpayers whose net income does not exceed €7,920 are exempted from the IR. In principle, taxable income is calculated from the income available to a fiscal household in one year. Some expenses by the household tax are deductible from total income. There can be cuts and maximum taxable amounts of the income.
The income tax is calculated by the administration based on the amounts reported by taxpayers who are required to declare their whole income earned during the previous year. But the calculation of income tax takes into account the personal situation of the taxpayer, in particular through the "family quotient" (or units in the household) on the one hand and in the allocation of reductions or tax credits to taxpayers, on the other hand. The family quotient can take into account family responsibilities and, according to them, eases the effects of progressive taxation since the progressive rate is applied to a partial income (the taxable income). This process consists of dividing the taxable income of the household tax into a number of units (or parts) equal to the number of individuals. The progressive scale of tax is then applied to taxable income per share. Finally, this partial tax is multiplied by the number of units to determine the taxable base.
The family quotient is one unit for a single person, two for a married couple, plus an extra half for each of the first two children and an additional unit for each child from the third.
There are certain limitations to the amount of tax savings that can be achieved under the parts system. If the system produces a tax bill which has been reduced by more than €2,301 (for 2009 income) per half part compared to what it would have been without reference to the parts, you are not allowed to use this system. You will always receive 2 parts for a married couple notwithstanding.
Various tax credits are available to set against the total tax calculated. These include tax credits for dividends, energy-saving work carried out on the main residence, purchase of an environmentally friendly car, employment of home help, child minding expenses, for filing tax returns electronically and paying tax by direct debit or electronically, for mortgage interest, among others.