Tax rates in Chargebee need to be managed manually. To Edit the countries you do business and respective tax rates go to Settings » Site Settings » Taxes » Click on EU VAT » Click the "Pen" icon to edit the Tax rate.
To Edit the tax rate, click on the "Pen" icon and enter the new tax rate.
Note: Chargebee does not provide an auto update function for taxes.
Feel free to reach out to our support team <firstname.lastname@example.org> if you have any questions.