Log in to the electronic tax bureau-select I want to do tax-enter the taxpayer identification number and login password, click Login-fill in the changes in the search box above, click Search to find the corresponding options among the options that appear, click on the information change of one household, choose to continue processing, jump to the information filling interface, find the mobile phone number that needs to be modified, fill in the latest mobile phone number, click Next to confirm the change information after confirmation, and click Submit.