Beginning with B2C Commerce 26.10, Multiple Tax Levels is generally available to all merchants. Your tax-provider integration can now store individual tax items on a line item, such as federal, state, county, or local tax. B2C Commerce aggregates those items into one tax amount and uses that amount for totals. There is nothing to turn on. Behavior is opt-in: if a line item has no tax items, you still set the aggregated tax value directly.
Where: This change applies to B2C Commerce in all editions. Shopper Baskets, Shopper
Orders, and Shopper Customers return the breakdown. Script API uses
LineItem.setTaxes() and LineItemTax.
How: Set up to 10 LineItemTax objects on a line item in a basket
calculation hook. Each tax item requires an ID and a rate. Value is optional; if you omit it, the
platform computes it. SCAPI returns the aggregate on tax and
taxRate, and the breakdown in taxItems as id,
rate, and value. Custom attributes are supported on
LineItemTax. Order export includes tax-items from version
26.5. Salesforce Order Management receives the individual tax items, including custom attributes
when the same custom attribute ID exists on both systems.