SIGNALS Documentation
API Reference

Tax Classes

Manage product and organisation tax classifications.

Overview

Tax classes categorise products and organisations for tax calculation. Signals uses two types of tax classes that work together to determine the applicable tax rate.

Product Tax Classes

Route: /admin/settings/tax/product-tax-classes

Product tax classes categorise items by their tax treatment (e.g. "Standard Rate", "Reduced Rate", "Zero Rated", "Exempt").

Action Description
Create Add a new product tax class
Edit Update name and description
Set Default Designate as the default for new products
Delete Remove a non-default tax class

One product tax class must be the default. The default class is applied automatically to new products. The default tax class cannot be deleted.

Organisation Tax Classes

Route: /admin/settings/tax/organisation-tax-classes

Organisation tax classes categorise members by their tax status (e.g. "Standard", "Tax Exempt", "Reverse Charge", "Charity").

Action Description
Create Add a new organisation tax class
Edit Update name and description
Set Default Designate as the default for new organisations
Delete Remove a non-default tax class

Organisation tax classes are assigned to members via the member edit form.

Tax Rates

Route: /admin/settings/tax/rates

Tax rates are named percentages (e.g. "UK Standard" at 20%, "Reduced" at 5%, "Zero" at 0%). Rates are referenced by tax rules rather than applied directly to products.

Action Description
Create Add a new named rate and percentage
Edit Update name, description, or percentage
Activate / Deactivate Toggle whether the rate is available for use
Delete Remove a rate

Tax Rules

Route: /admin/settings/tax/rules

Tax rules map a combination of organisation tax class and product tax class to a tax rate. When more than one rule could apply, the rule with the highest priority wins. Each rule can be activated or deactivated without deleting it.

Action Description
Create Map an organisation tax class + product tax class to a tax rate, with a priority
Edit Update the class pair, rate, or priority
Activate / Deactivate Toggle whether the rule participates in resolution
Delete Remove a rule

How Tax Classes Work

When calculating tax on a line item, Signals considers both the product's tax class and the organisation's tax class. The tax calculation engine resolves the highest-priority active tax rule for that class pair and applies its tax rate to compute the final tax amount. If no rule matches, no tax is applied.

The same resources are available through the Tax Classes API for programmatic management.