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.
9世紀末頃より、租庸調・雑徭・正税などといった律令制に基づく税体系が解体され始め、まず地方（国衙）レベルの徴収において官物と臨時雑役に分けた賦課・徴収が行われるようになり、次第に中央（朝廷）レベルでも同様の徴収が行われるようになっていった。