WooCommerce coupon code not working

Why it happens

Restriction collisions. Coupons carry three restriction sets that interact: usage limits (per coupon, per user, per email), product/category restrictions, and exclusions (sale items excluded, or specific products excluded). A code advertised store-wide fails for the customer holding one sale item. The campaign copy and the coupon settings disagree; the customer loses.

Minimum spend math. Minimum spend is calculated on the cart subtotal and its after-coupon behaviour depends on settings: a second coupon can push the cart below the first coupon’s minimum and invalidate it, producing “coupon cannot be applied” with no explanation.

Expired or paused quietly. Expiry dates, usage caps reached, or a plugin that pauses coupons (maintenance mode plugins, membership plugins restricting to members).

Stacking rules. By default only one coupon applies per cart; “apply with other coupons” is a checkbox people miss, so the loyalty code silently rejects the sale code.

Triage

Reproduce in incognito with the intended cart. Read the exact rejection message, it names the failing check (usage limit, minimum spend, excluded product). Open the coupon: usage count vs limit, expiry, restrictions tab, exclusions. Fix the mismatch between what the campaign promises and what the coupon permits, then re-test with the customer’s actual scenario.

When to bring us in

If your campaigns keep dying on coupon edge cases, or you need stacking rules, role-based pricing, B2B codes or auto-applied promotions that behave predictably, that is WooCommerce development work we do regularly. One scoped fix ends the support tickets from customers holding valid codes that bounce.