Suanfu 算賦, the poll tax, was created by Shang Yang 商鞅 (390-338 BCE) in the state of Qin 秦 during the Warring States period 戰國 (5th cent.-221 BCE). The Han dynasty 漢 (206 BCE-220 CE) adapted it. Emperor Gaozu 漢高祖 (r. 206-195 BCE) ordered in 203 BCE that each male person between the age of 15 and 50 sui was liable for the payment of 120 qian 錢 of money (one suan 一算) as poll tax. The levy was carried out each year in the eighth month in a procedure called anbi 案比. The taxed population was called bayue suanren 八月算人.
The revenue from the poll tax was mainly used for the supply of troops and the purchase and management of chariots and horses, and therefore a kind of military tax (junfu 軍賦). Gong Yu's 貢禹 suggestion during the reign of Emperor Yuan 漢元帝 (r. 49-33 BCE) to life the age of tax liability to 20 sui was not adopted. The tax was normally levied in money, barring a few exceptions during the reign of Emperor Zhao 漢昭帝 (r. 87-74 BCE), when the grain price was so low that he ordered to substitute the money by beans or millet.
The height of the the suanfu tax was relatively moderate, and sometimes even exceptionally lowered to 80 qian (under the reign of Emperor Wen 漢文帝 (r. 180-157 BCE) and in 31 BCE) or to 90 qian (in 52 BCE). On some occasions the central government waived the tax payment (see juanmian 蠲免). Emperor Wen even lowered the conversion rate of suan and qian to 1 : 40, but the great martial Emperor Wu 漢武帝 (r. 141-87 BCE) raised it again to 1 : 120, in order to finance his many conquest projects. During the reign of Emperor Ling 漢靈帝 (r. 167-189) of the Later Han 後漢 (25-220 CE) an additional amount of 40 qian was levied for repairing Southern Palace 南宮 that had been damaged by fire.
The tax was normally levied per head, but during the Qin period households with more than 2 male persons did only pay the amount twice. In order to promote the economic situation of the empire, Emperor Hui 漢惠帝 (r. 195-188) of the Han ordered in 189 BCE to marry young and imposed a fivefold poll tax on unmarried girls older than 15 and not married with 30 sui. During the early Han, merchants (guren 賈人) and private slaves (nubi 奴婢) paid twice the normal amount. By this measure the government attempted to suppress wealthy merchants and rich persons. The usurper Wang Mang 王莽 (r. 8-22 CE) repeated this measure and taxed merchants and slaves with an amount of 3,600 qian which was the thirty-fold of normal persons.
Persons below the age of 15 sui paid a different kind of poll tax called koufu 口賦, kouqian 口錢 or koufu qian 口賦錢. This type of tax seems to have existed already under the Qin, but only under the Han the poll tax was split up into one imposed on adults (suanfu), and one on children (koufu). In the early Han period children between 7 and 14 sui paid 20 qian of poll tax, but Emperor Wu lowered the age to 3 sui and added a special levy of 3 qian to finance army horses ( 馬口錢). While the suanfu tax belonged to the revenue of the Chamberlain for National Treasury (dasinong 大司農), the koufu tax was an income of the Chamberlain for the Palace Revenues (shaofu 少府), but was allotted to the military expenditure, which in turn was liable to the National Treasury. Gong Yu suggested to Emperor Yuan to go back to the original age, but the amount of 23 qian became the regular one for the koufu tax.
In later years it was only occasionally levied, but again applied extensively to suppress the many rebellions of the late Eastern Han period. At that time, even toddlers had to pay the tax. The tax was according to some contemporary authors quite detrimental to the birth rate because poor peasants preferred to kill their newborn babies in order to escape the tax. At some occasions the government resigned from the payment for several years. In 204 the koufu tax was therefore transformed into a household tax (hudiao).
The levying of these taxes in the form of money instead of in kind supported the rise of a monetary economy, at least to a certain extent. In later ages the form of the poll tax was changed and called differently. During the Tang period 唐 (618-907), in the tripartite tax system (zuyongdiao 租庸調) it was called yong 庸, during the Song period 宋 (960-1279) dingqian 丁錢, during the Yuan 元 (1279-1368) dingshui 丁稅, and dingfu 丁賦 or dingyin 丁銀 under the Ming 明 (1368-1644) and Qing 清 (1644-1911) dynasties, but the last two merged the poll tax with the field tax (see yitiaobian fa 一條鞭法 and tanding rumu 攤丁入畝).