Tax‑Proof Coupons for WooCommerce lets you define an eligible fixed-cart coupon as a gross amount: the amount your customer should actually see deducted after tax.

What does it do?

The plugin adds an Apply coupon after tax checkbox to the coupon editor. It can be enabled only for fixed-cart coupons. When the option is enabled, each part of the coupon is converted using the tax rate of the product line it discounts.

For example, a 35.00 EUR coupon reduces eligible products by 35.00 EUR including tax, within the configured currency precision. WooCommerce still stores the required net discount and tax portion internally.

This is useful when a fixed promotional value should not become larger or smaller merely because eligible products use different VAT rates or the customer’s tax location changes.

What are the limits?

Only fixed-cart coupons with Apply coupon after tax enabled are changed. For other coupon types, the option is disabled and explains why it is unavailable; those coupons keep WooCommerce’s native behavior.
The effective discount cannot exceed the value of the eligible product lines. Shipping, fees, excluded products, and other non-discountable amounts do not increase that limit.
Displayed and stored amounts follow WooCommerce’s configured currency precision and rounding.
The plugin does not choose tax rates, change product prices, replace a tax engine, or provide tax or legal advice.

Compatibility

Version 1.0.9 is tested with WordPress 7.0, WooCommerce 10.9.4, Checkout Block, High-Performance Order Storage (HPOS), Germanized 4.0.10, and Germanized Pro/StoreaBill 4.3.4. The 1.0.9 admin change does not alter the invoice or coupon calculation paths verified with finalized StoreaBill PDFs in 1.0.8. Dedicated compatibility paths exist for WPML/WooCommerce Multilingual and Germanized Pro/StoreaBill. Compatibility still depends on the versions and configuration used by the store; report reproducible conflicts through the GitHub issue tracker or WordPress.org support forum.