Power of attorney. The document signed by the taxpayer is generally a power of attorney, that is, the taxpayer authorizes an agent to handle related matters on his behalf. For example, taxpayers can authorize their agents to complain to the tax authorities, handle tax cancellation, receive invoices and other matters through power of attorney, and these power of attorney will only take effect after the taxpayer signs and seals. Other similar power of attorney include, for example, opening a financial account, bank authorization, legal agent authorization, etc.