Legal analysis: 1. Taxpayers who overpay taxes shall be refunded immediately after the tax authorities find out. Taxpayers may request the tax authorities to refund the overpaid tax, plus interest on bank deposits for the same period, if they find it within 3 years from the date of final settlement and payment of taxes. 2. If the taxpayer pays less tax due to the responsibility of the tax authorities, the tax authorities may require the taxpayer to pay back the tax within three years, but shall not impose a late fee. If the taxpayer underpays the tax due to mistakes, the tax authorities may recover the tax and late fees within 3 years. Under special circumstances, the recovery period can be extended to 5 years. For tax evasion, tax fraud and refusal to pay taxes, the tax authorities may recover taxes and late fees indefinitely.

Legal basis: Article 2 of the Individual Income Tax Law of People's Republic of China (PRC), individual income tax shall be paid for the following personal income: (1) income from wages and salaries; (2) Income from remuneration for labor services; (3) Income from remuneration; (4) Income from royalties; (5) Operating income; (6) Income from interest, dividends and bonuses; (7) Income from property lease; (8) Income from property transfer; (9) Accidental income. Individual residents who obtain income from items 1 to 4 of the preceding paragraph (hereinafter referred to as comprehensive income) shall calculate individual income tax according to the tax year; Non-resident individuals who obtain income from items 1 to 4 of the preceding paragraph shall calculate individual income tax on a monthly or itemized basis. Taxpayers who obtain income from items 5 to 9 of the preceding paragraph shall calculate individual income tax separately in accordance with the provisions of this law.