Hi,

For handling united states taxes, you can activate the avalara / avatax or tax cloud option from the accounting settings and then the tax cloud will return the tax rates based on the customer category and customer location.

Both integrations allow you to correctly calculate the sales tax for every address in the United States and keeps track of which products are exempt from sales tax and in which states each exemption applies. Odoo then calculates sales tax in real-time for every state, city, and special jurisdiction in the United States.

See:

https://www.odoo.com/documentation/master/applications/finance/accounting/taxes/avatax.html

https://www.odoo.com/documentation/master/applications/finance/accounting/taxes/taxcloud.html

Thanks