According to the provisions of the Law of People's Republic of China (PRC) on Tax Collection and Administration, the tax authorities may require taxpayers to provide invoices, account books, vouchers and commercial documents related to tax payment. In practice, the copy of the maintenance fund invoice has certain legal effect, but the authenticity and legality of the copy need to be recognized and audited by the tax authorities. Under normal circumstances, when accepting the reimbursement of maintenance funds, the relevant departments and units require the original invoices to ensure the authenticity and legality of the invoices. However, in some special cases, if the original invoice is lost or damaged and the original cannot be provided, a copy of the invoice can be provided, but measures such as official seal are needed to prove its authenticity. Therefore, if it is necessary to use a copy of the maintenance fund invoice as proof material, it is recommended to communicate with relevant departments and units in advance, and provide the original invoice as much as possible or get the approval and audit of the tax authorities to ensure legality and authenticity.