Legal analysis: ukey electronic invoice is not as effective as electronic seal, and the invoice issued by tax UKey has two chapters, only showing the tax producer's chapter, which is normal and has the legal effect of VAT invoice. Use OFD reader to open the downloaded format file, and right-click the tax producer seal on the electronic invoice for verification. Replacing the original invoice special seal with reliable electronic signature, and replacing the original invoice producer seal with the electronic invoice producer seal signed by tax digital certificate, better meet the needs of electronic invoice reform.

Legal basis: Measures for the Administration of Invoices in People's Republic of China (PRC).

Article 3 The term "invoice" as mentioned in these Measures refers to receipts and payments vouchers issued and collected in business activities such as the purchase and sale of commodities, provision or acceptance of services, including paper invoices and electronic invoices.

The State promotes the use of electronic invoices, and the specific measures for the administration of electronic invoices shall be formulated by the competent tax authorities of the State Council. Units and individuals that develop electronic invoice information systems for their own use or provide electronic invoice services for others shall abide by the regulations and standards for the supervision of electronic invoices formulated by the competent tax authorities in the State Council.

Article 4 The competent tax authorities in the State Council shall be in charge of the national invoice management. The tax authorities of provinces, autonomous regions and municipalities directly under the Central Government shall, according to their duties, do a good job in invoice management within their respective administrative areas.

Finance, auditing, market supervision and management, public security and other relevant departments shall, within the scope of their respective duties, cooperate with the tax authorities to do a good job in invoice management.

Article 5 The types, copies, contents, coding rules and scope of use of invoices shall be stipulated by the competent tax authorities of the State Council.

Article 6 Any unit or individual may report any violation of laws and regulations on invoice management. The tax authorities shall keep confidential the informants and reward them as appropriate.