> For the complete documentation index, see [llms.txt](https://help.dollarlabs.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.dollarlabs.io/dollarlabs-ultimate-discounts/unified-discount-engine-v2/limits/reject-discount-codes.md).
# Reject discount codes
## Prevent Loyalty Coupons from Stacking with Sale Discounts
Running automatic sales like **10% off sitewide** is great—but many merchants don’t want **loyalty coupons** to stack on top of those discounts.
This article shows you how to **automatically reject loyalty discount codes at checkout** when a sale is already applied, without manually configuring Shopify combination rules for hundreds (or thousands) of codes.
{% embed url="" %}
***
### The Problem
Most loyalty apps generate **a large number of discount codes**, often dynamically.
Examples:
* `BH_XXXX` (Bubblehouse)
* `SMILE_XXXX`
* `BONN_XXXX`
Shopify’s native **discount combination rules** don’t scale well for this:
* You must explicitly configure which discounts can combine
* It’s impractical when loyalty apps constantly generate new codes
* Managing this manually is error-prone and time-consuming
***
### The Solution: Reject Discount Codes at Checkout
Instead of trying to control **combinations**, you can **reject specific discount codes** at checkout when a sale (automatic discount) is active.
This allows you to:
* Run automatic sales (10%, 20%, etc.)
* Block loyalty coupons from applying on top
* Clearly communicate *why* the coupon was rejected to the customer
***
### How It Works (High Level)
When an automatic discount is applied:
* The app checks any discount code entered at checkout
* If the code matches your rejection rules → it’s rejected
* A custom message explains why the code didn’t apply
***
### Step-by-Step Setup
#### 1. Create or Open Your Sale Discount
* Create an **automatic discount** (example: 10% off all products)
* This can be product-based, order-based, or sitewide
***
#### 2. Open **Create Unified Discount**
* Navigate to **Create Unified Discount**
* Select **Product Discount** (or the relevant discount type)
* Define your rules and targets (e.g., all items in cart)
***
#### 3. Enable **Reject Discount Codes**
Inside the discount config's settings, enable **Reject Discount Codes**.
You’ll see a small configuration module with the following options:
***
#### 4. Choose a Match Type
**Option A: Exact (Fits)**
* You manually list specific discount codes to reject
* Best for small, fixed sets of codes
**Option B: Pattern (Recommended)**
* Automatically rejects codes based on a pattern
* Ideal for loyalty apps that use prefixes or formats
***
#### 5. Configure the Match Operator (Pattern Only)
Choose how the code should be matched:
* **Starts with**
* **Ends with**
* **Contains**
Example:
* Starts with → `BH_`
* Starts with → `SMILE_`
* Contains → `LOYALTY`
This works because most loyalty apps follow a consistent naming format.
***
#### 6. Set the Rejection Message
Add a message that customers will see at checkout.
**Example:**
> “Loyalty coupons are not valid for this order.”
You can fully customise this message to match your brand tone and explain that a sale is already applied.
***
### What the Customer Sees
* The automatic sale discount remains applied
* When a loyalty code is entered, it’s rejected
* The customer sees a **clear reason**, not a silent failure
* No confusion or “random” discount behavior
***
### When Should You Use This?
This setup is ideal when:
* You’re running **automatic sales**
* You use **loyalty or rewards apps**
* You don’t want double-discounting
* You want a clean, scalable solution without managing combinations
***
### Key Benefits
* No need to manage Shopify combination rules
* Works with **dynamic discount codes**
* Scales across all loyalty apps
* Improves checkout clarity and trust
* Fully configurable messaging
***
### Need Help?
If you have:
* Multiple loyalty apps
* Complex discount logic
* Edge cases you’re unsure about
Reach out via **chat or support email**—we’re happy to help you set up even the most complex discount scenarios
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:
```
GET https://help.dollarlabs.io/dollarlabs-ultimate-discounts/unified-discount-engine-v2/limits/reject-discount-codes.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.