Plugin Contributor
Phil
(@fullysupportedphil)
Automattic Happiness Engineer
Hey @armando_e,
Once the user is redirected back to your cart with their address info, the tax should automatically update.
Can you first check that your taxes are properly set up for your customers under WooCommerce > Settings > Standard Rates. Ensure that you haven’t placed city, state or zip code restrictions on your taxes that you don’t want. Also check to make sure that you have your taxes set to calculate based on your customer’s address:

Image Link: http://cld.wthms.co/wbqw/1OZ1JdqG
If that doesn’t help, please try disabling all plugins except for WooCommerce and WooCommerce PayPal Express Checkout. Test again to see if the problem is resolved. If not, temporarily change your theme to the default [Twenty Sixteen](https://en-ca.wordpress.org/themes/twentysixteen/) WordPress theme. If the problem goes away after either step, you have a conflict that is causing the issue. You can then reactive your plugins/theme, one at a time. Check after each one to see when the issue returns. You’ll then need to reach out to the developer of the plugin/theme that is causing the conflict in order to get an update.
If none of those steps help can open a ticket by going to http://www.WooCommerce.com, then click on Support > Helpdesk > Create a ticket > Free plugins.. Please make sure to include a temporary Administrator username and password with your message, so that our team can take a look at your site.