Payment of Islamic taxes is considered a religious duty. The most important tax is zakah, which is based on wealth and paid annually. Cash holdings, asset disposals, and inventories are subject to tax at a standard rate of 2.5 percent. Zakah is to be paid by those with surplus liquid wealth for the benefit of the poor and needy, typically via spending on social and humanitarian causes. The collection of zakah is usually organized separately from that of state taxes. Another traditional Islamic tax was the jizyah, or poll tax, paid by non-Muslim residents of a Muslim state to the government in exchange for government protection. The Islamic land tax (kharaj) is applied to both Muslims and non-Muslims according to acreage of land, with the rate depending upon output potential and a maximum rate of half of the crop value.