The CartValidate doesn't include tax calculations. Use the CartPrepare workflow if you want to calculate taxes on a cart. The code for that could be:
CartHelper.RunWorkflow("CartPrepare")
or
Cart.RunWorkflow(OrderGroupWorkflowManager.CartPrepareWorkflowName)
The OrderGroupWorkflowManager contains static string variables for each of the three workflows used for carts out of the box.
Here's more documentation on the workflows to better understand them:
http://world.episerver.com/Documentation/Items/Developers-Guide/EPiServer-Commerce1/751/Workflows/Workflows/
The other thing to remember is that Tax calculations can only ever calculate a non-zero tax value for Line Items that
Hi,
I have set up a UK TAX with a rate of 20 and then attached this Tax category to my product variants but on the Basket page my TaxTotal is always ZERO.
Is this a bug in Commerce or have I missed something?
Jon