California Portal Access Instructions

To provide Zamp with access to your California CDTFA Online Services account, you will need to add our filing email (filing@zamp.com) as your authentication email so we receive authorization codes at login. Once we have access, we can:

  • Connect our third-party filing account so we can file on your behalf
  • Make other updates to your account to ensure we receive important tax-related correspondence from the state

Here are the steps to add our filing email to your account:


1) Open 'Settings' in your CDTFA Online Services account

Log in to your account at https://onlineservices.cdtfa.ca.gov/_/. Once you've logged in, select the 'Settings' button in the top right:


2) Edit your Logon settings

Select the 'Edit' button next to your Logon information:


3) Update your Authentication settings

  • Set the Authentication Type to 'Send authentication email'
  • Update the email to filing@zamp.com