What if I don't know the FROM address at time of tax estimation?
If you do not have the FROM address when calculating sales tax, you can get tax rates for a given location by using the /v2/rates endpoint and providing the customer's address. You can then use the customer's tax rate and multiply it by the amount of the sale. This is a rough estimate and in some cases will be wrong, especially if the seller does not have nexus in that state.
It is highly recommended to use the FROM address of the merchant selling the product (or multiple addresses) using the `from_` or `nexus_addresses` parameters with the /v2/taxes endpoint. This will provide the most accurate sales tax calculation and determine if sales tax is actually due.