1, Tax Law: According to the national tax law, there are some restrictions or quotas that limit the scope or amount of tax refund for individual tax settlement. For example, certain types of income are not allowed to be refunded, or the amount of tax refund is limited.

2. Other taxes payable: In addition to personal income tax, taxpayers also have other taxes payable, such as property tax, vehicle and vessel tax, etc. If the taxpayer has other unpaid taxes, the tax refund for individual tax settlement will be restricted.

3. Violation: If the taxpayer violates the rules, such as tax evasion, tax evasion, etc. The tax authorities will supervise the handling and limit his right to settle the tax refund.

4. Audit by tax authorities: The tax authorities will verify and investigate the income and expenditure of taxpayers when auditing their tax returns. If there are irregularities or unreasonable circumstances, the amount of tax refund will be limited.