Cartthrob order subtotal:plus_tax includes tax on products that aren't taxable

Question

I have a cart set up to add 20% VAT to products. We then have a field that enables the user to set a product as non-taxable.

When you order one of these products, everything goes through as expected with the order confirmation showing the line item without tax, and the order tax and grand total in the summary are all incorrect. However the subtotal is not - it adds tax when it shouldn't.

Example:

Product price = £15.42, not taxable.

Subtotal = £18.50 Shipping = £0.00 (Incl. tax)= £0.00 Total = £15.42

This is with the following code:

{exp:cartthrob:submitted_order_info}
    Subtotal: {order_subtotal:plus_tax}<br>
    Shipping: {order_shipping:plus_tax}<br>
    (Incl. tax): {order_tax}<br>
    Total: {order_total}
{/exp:cartthrob:submitted_order_info}

I've tried removing :plus_tax but then the output is incorrect for any products that DO have tax on them.

This only seems to affect the subtotal and order_shipping in the submitted_order_info tag, both of which fine all the way through the basket.

EE is 2.7.2, CT Pro 2.4

Answer 1

Rather than use :plus_tax on the order_subtotal tag, the solution was to map a field in the config for Order Subtotal Plus Tax and just output that directly in the template (for example {order_subtotal_plus_tax}.