(1) The classified income tax is unreasonable. From the perspective of tax law theory, the income tax system can be divided into three types: classified income tax system, comprehensive income tax system and classified comprehensive income tax system. The legislative basis of classified income tax lies in the application of different tax rates to different types of income and the implementation of differential treatment. It can not only control the tax source, but also save the collection fee, but it can not better reflect the principle of fair tax burden. The comprehensive income tax system reflects the actual burden level of taxpayers and conforms to the principle of ability to pay and the principle of taxation according to capacity. Its drawback is that tax collection is cumbersome and it is easy to cause tax evasion opportunities. At present, China adopts a classified income tax system. That is to say, all personal income is divided into 1 1 categories, and then applied to different deduction ranges and tax rates for collection. For example, Zhang San and Li Si both earn 3,200 yuan a month, but the difference is that Zhang San's income comes from salary. Half of Li Si comes from salary and the other half comes from other income. For example, according to the current classified collection system, Zhang San's 3200 yuan salary income is 1600 yuan, 1600×10%-25 = 135 yuan after deducting the fixed expenses of1600 yuan, so Zhang San has to pay taxes/. However, Li Si's salary income is 1600 yuan, and after deducting fixed expenses 1600 yuan, his taxable income is 0; 800 yuan, the taxable income is 0 after deducting the deduction of 800 yuan expenses; In the end, Li Si didn't pay any taxes. It stands to reason that people with the same ability to pay taxes should pay different taxes, which results in the unfairness of taxpayers. If the personal income tax adopts the comprehensive collection system, Zhang San and Li Si will have to pay the same personal income tax in the end, although their income types are different. Some people think that the classified collection system is in line with China's national conditions. From the development trend, China's Individual Income Tax Law should adopt a classified comprehensive income tax system. Because, although the classified income tax system is convenient to calculate, it can not better reflect the principle of tax fairness and effectively eliminate the difference in taxpayer burden; Although the comprehensive income tax system can eliminate this difference, it also discriminates against income from different sources. The classified comprehensive income tax system combines the advantages of the above two types of tax systems. In China, the income from work, salary, contracting and subcontracting is combined into comprehensive income, and after reasonable expenses deduction, the cumulative tax rate is applicable, and the rest is applicable to the proportional tax rate. However, as far as China's current actual situation is concerned, the construction of social legal system is lagging behind, citizens' awareness of tax payment is weak, tax collection and management methods are backward, and the quality of tax collectors is low. In this case, if we rashly change from classified taxation to comprehensive taxation, the cost of institutional change will be enormous. For example, for taxable items that are investment and have no expense deduction. On the basis of the combination of this classification and comprehensive income tax, with the improvement of the tax environment, China's individual income tax law may finally smoothly transition to the comprehensive income tax model.

(2) The deduction of expenses is unreasonable. Take the deduction of salary expenses as an example. The current personal income tax law stipulates that those who get a salary will be deducted 1600 yuan every month. Suppose Zhang San is a family of three. He, his wife and children, his wife are unemployed or laid off, and his monthly income is 2000 yuan, while Li Si is a family of five. Other things are the same, except that there are two old people at home. According to the current individual income tax law, Zhang San has to pay 20 yuan tax every month, and his after-tax income is 1980 yuan, with 660 yuan per capita. However, after Li Si pays 20 yuan tax, his per capita tax income is only 396 yuan, a difference of 264 yuan. As a result, the apparent equality resulted in the de facto inequality. Why did this problem arise? The reason is that the actual situation of taxpayers must be considered in the current expense deduction of personal income tax in China. If the fixed family expenses are deducted, it should be calculated according to the actual population supported by the family. In addition, we should also consider the deduction of supporting the elderly and raising children, hospitalization for serious illness, education and training, and the purchase of the first house. Through this deduction, taxpayers can pay taxes at a fair starting point and avoid the unfairness in taxation caused by simplification of deduction.

(3) Unreasonable tax rate. At present, China's personal income is taxed at a nine-level progressive tax rate of 5%-45%, but the income from interest, dividends, bonuses, property leasing and property transfer is taxed at a proportional rate of 20%. Among them, the highest tax rate of wages is 45%. Obviously, the highest tax rate of the former is far greater than that of the latter, which inhibits people's enthusiasm for work to a great extent and affects the implementation of the principle of distribution according to work. This is one of them. Secondly, there are too many and complicated grades in the nine-level excess progressiveness, which violates the principle of simplification and efficiency of the individual income tax law. Moreover, according to the current level of our country, the proportion of people who really reach level 5 or above is extremely small. Drawing lessons from western experience, in the tax reform after 1988, the United States changed the original11%-50% personal income tax to 15% and 28% bipolar tax rates; Britain has changed from the original 6-level excess progressive tax rate of 27%-60% to 25% and 40%. In contrast, China's wage income tax rate is high and the grade is cumbersome. This is not conducive to attracting foreign investment in China, not conducive to foreign experts coming to work in China, and of course not conducive to stimulating the enthusiasm of individuals for work, investment and savings.

(4) Unreasonable tax collection and management system. First, income channels are diversified. With the development of economy, in addition to normal work, people increase their income sources through various channels such as stock trading and part-time jobs. Such a taxpayer can obtain taxable income through various methods in the same tax payment period, and besides, the taxpayer can have several account numbers in the bank. The bank is not clear, let alone the tax. Second, citizens' income is more in cash. Small-sum transactions are usually completed through the exchange of cash and goods. There is no direct contact with the personal account of the bank, and the income is difficult to control. Third, it is carried out by illegal means, which is easy to cause the loss of tax sources. Reform the personal income tax collection and control system, and form a collection and management model based on tax declaration, guaranteed by tax inspection and supplemented by tax agents. The revised Individual Income Tax Law adopts the method of source collection as the main method, supplemented by self-declaration. In order to strengthen the control of tax sources and plug tax loopholes, it is more practical to implement the tax collection method based on withholding and remitting. From the perspective of cultivating citizens to consciously fulfill their tax obligations, we should reform in the following aspects:

1, personal income payment standardization and credit. That is to say, personal income from any source, whether it is salary income, labor remuneration, contract income, manuscript fee income, property lease and transfer, dividend, interest and bonus income, accidental income and other income, is paid by bank transfer, and direct payment in cash is avoided as far as possible. Because, as long as it is cash payment, it is difficult to monitor and avoid tax evasion. In foreign countries, even in developed countries where the market mechanism is quite sound, the tax authorities can't do anything about the underground economic mechanism and other economies that pay directly in cash. First, deposits must implement the real-name registration system and personal economic identity card system; Second, income from any source must be credited to the deposit account of your main payment bank through the bank; Third, banks must be networked, even with financial savings, large shopping malls, hotels, aviation, railway and road transportation companies. This is not only convenient for individuals, but also beneficial to the monitoring of banks and tax departments, and of course beneficial to the taxation of tax departments.

2, must strictly implement the withholding system. Judging from the practice of collecting personal income tax at home and abroad, in order to effectively collect personal income tax, it is necessary to implement a strict withholding system, that is, the source deduction tax system. This is especially important under the condition of diversified and non-standardized income sources in China. One of the main reasons why it is difficult to effectively collect personal income tax in recent years is that the units or individuals who pay personal income rarely or even seriously implement the obligation of withholding and remitting. There is a connection between the unit and the individual who pays personal income, and they try their best to evade taxes and fail to seriously implement the obligation of withholding and remitting. Therefore, in order to effectively collect personal income tax at zero point, the withholding and remitting system of personal income tax must be established. In order to achieve this goal, urge units or individuals to earnestly fulfill their withholding obligations. For example, employers should regularly report the details of personal payments to the tax authorities for supervision, and units and individuals who fail to fulfill their withholding obligations must be severely punished. If a unit or individual fails to perform the obligation of withholding and remitting, once verified, in addition to paying back the unpaid tax, a fine of five or even ten times the unpaid tax may be considered, which shall be recorded and disclosed to the public.

3. Establish a personal credit restraint mechanism of the whole society. People often think that the lack of tax evasion in western countries is not only due to the high moral quality of western citizens and strong tax awareness. More importantly, western countries have established a set of relatively perfect personal reputation mechanisms. Just like the "high-paying group", that is, once an individual or enterprise or company evades taxes, it will be recorded by the relevant social authorities, that is, blacklisted. Will face discredit, no one dare to hire, no one dare to deal with it. As a result, the cost of tax evasion is extremely high, thus effectively preventing tax evasion by citizens and enterprises. However, in our country, due to the lack of a strict personal social reputation restraint mechanism. Taxpayers often try their best to escape if they can, and even collude with tax department personnel to give benefits to tax staff and let them go, resulting in a major loss of tax sources. Because of the imperfection of the system, it is sometimes difficult for tax department personnel to grasp the income of taxpayers, which makes it extremely unlikely that they will be investigated. Even if they are investigated, they will only be fined, and the cost paid is extremely small, so many people take risks and it is difficult to contain them. Some of them are even proud of not being ashamed, but do not change after repeated education, and go their own way. This requires us to establish a social reputation file platform covering individuals or units in the whole society, and the information will be made public. Once an individual or unit evades taxes, it will be recorded in the file. Due to the openness of information, anyone who hires individuals or units to do transactions will first consult the archives center for the sake of insurance. In this way, the phenomenon of tax evasion of personal income tax will be greatly reduced.