"Rinjizoyaku" is a collective term for the odd-job tasks that kokuga (provincial government office) obliged local farmers to perform as a kind of tax payable in labor or in kind. There was no tax called 'Rinjizoyaku,' but the word was used to refer collectively to taxation in the form of forced labor imposed on the people in the name of 'dairizatsuji' (miscellaneous chores in the palace), 'cho no kobai kinu' (acquisition and purchase of silk), etc.
Since the end of the 9th century, the tax system had been based on the Ritsuryo system, with Soyocho (taxes on rice, labor or alternative goods, and textile goods or alternative money), Zoyo (irregular corvee), and Shozei (the rice tax stored in provincial offices' warehouses), however, this system was gradually dismantled, and at the local (kokuga) level, dual taxation consisted of Kanmotsu (tribute goods paid as taxes or tithes) and Rinjizoyaku began to be imposed and collected, and gradually this way of taxation extended to the central (Imperial Court) level. Rinjizoeki is considered to be a modified form of the corvee imposing forced labor, but later other elements, such as Kyoyaku (a task to acquire the necessary materials for the State and kokuga, using the rice collected through the Soyocho and other tax levying system) were added. Rinjizoyaku was imposed on the manors (shoen) as well as public lands, and sometimes the lord of manor asked the kokuga for exemption from Rinjizoyaku.