Stop codes from stacking

Customers combining multiple codes on one order is the most common discount leak — each code came from a different campaign, and nobody planned for them to meet. This guide turns that off in about a minute.

1. Open Controller in PromoLock.

2. On the Discount Code tab, find the Discount Stacking Lock card and turn its switch on.

3. Optional — add Stacking exceptions: codes that may always be applied, even alongside another code. A free-shipping code you want combinable belongs here. Patterns work, so SHIP# covers every code starting with SHIP.

4. Optional — write your own Error message (what the customer sees when their extra code is rejected). Left blank, checkout shows “Discount combination not allowed.”

5. Hit Save in the save bar. The lock is live at checkout immediately.

How it behaves

When a customer applies two or more codes, the first code is kept and the extras are rejected with your message — the customer keeps their best-known discount, they just can’t pile more on. Exception codes are invisible to the limit: they always apply and don’t count toward it.

Check it worked

Open your storefront, add something to cart, and apply two discount codes at checkout. The second should be rejected with your message. On the PromoLock dashboard, the Controller card now shows Stacking lock — On.

Related

• The stacked discounts report shows what stacking was costing you — watch it fall after enabling the lock.
• Discounts you create in PromoLock also have per-discount Combines with flags — the lock and those flags work together.