After completing the industrial and commercial registration, obtaining the tax registration certificate and completing the taxes approved by the relevant tax bureaus, if an enterprise wants to apply for online electronic tax return, it should apply to the competent tax authorities for online tax return, receive and fill in the Approval Form for E-mail (Electronic) Declaration Application, Form for Application (Renewal) of Unit Certificate and Letter of Responsibility for Application (Renewal) of Unit Certificate, and submit the completed forms to the acceptance department of the competent tax authorities. Attach the following documents: 1, copy of organization code certificate (copy), copy of enterprise business license (copy), CA certificate and copy of operator ID card registered by users. After the competent tax department accepts the application, it will notify the enterprise to go to the software service provider designated by the tax bureau for training and get the CA certificate USB flash drive. Download and install online tax filing software To realize online tax filing, you must first have a computer with Internet access and install an electronic tax filing software client. Shanghai uses eTax@SH online tax declaration system. Put the CD provided by the service provider into the computer CD-ROM drive, or download the online tax filing system software eTax@SH (client) from the service provider's website for installation. Similar to the installation of ordinary software, follow the installation instructions of eTax@SH system software and/or the prompts of software installation process until the online tax filing software eTax@SH is installed.