Flash Sale Mode is not necessary for Shopify Native merchants, and should not be enabled.
Flash Sale Mode – Overview & Order Flow
Flash Sale Mode is designed for your most high-traffic events (such as product “drops” or limited-time sales) to maximize checkout stability, prevent overselling, and protect the customer experience. Once activated, all orders will process with real-time stock validation (requires merchant development — see below, “Technical Requirement”), and fast payment methods (i.e., credit cards only) to handle high traffic. It can be switched ON or OFF in the Global-e Admin by merchant users with the Merchant CS Admin role, or by special per-product activation. It can also be switched on by the Global-e NOC team if you alert us about your sale ahead of time. Please note: If your sale may result in over 300 orders/minute, please reach out to the Global-e Client Success team for additional support.Enabling Flash Sale Mode
Enable for All Orders (Global Activation)
- Turns Flash Sale Mode ON for all checkouts in the Global-e Admin portal under Merchants → Flash Sales → Start Now (for users with the CS Admin role).
- Use this for site-wide flash sales, such as Black Friday or other major promotional events.
- Activation is immediate for any newly opened checkouts. Once it is enabled, click the Stop button to deactivate it.
Schedule a Flash Sale (Scheduled Activation in Portal)
- Set up and schedule your flash sale ahead of time via the Global-e Admin Portal under Merchants → Flash Sales → Add New Schedule (for users with the CS Admin role).
- You can define the exact start and end time for your sale — ideal for events that need to go live at a specific moment (e.g., a new collection drop).
- All orders received during the active window will follow the Flash Sale checkout flow.
Enable for Specific Items (Per-Item/Product Activation)
- Flash Sale Mode is triggered only when certain products are in the shopper’s cart — this gives you precise control and flexibility.
- This method is perfect for limited-time product drops or sales targeting only select items.
- Add a special “IsFlashSale” attribute to each flash sale item in your cart payload, as shown below (platform specific).
- If any product in the cart contains this attribute, Flash Sale Mode will activate automatically for that checkout session, even if the overall store setting is OFF.
Oversell Protection
During a flash sale, every order submission triggers a real-time request to your SendOrderToMerchant endpoint to verify stock before payment is finalized or confirmation is shown. If all items are in stock: your backend returns a standard success response and the order is completed. If any item is out of stock: your backend must respond with error code 1100 (which is the default code). This tells Global-e that the order cannot be fulfilled, blocks the order, notifies the customer that an item is unavailable, and redirects them back to the cart page.Technical Requirement: Out-of-Stock SOTM Response
Your backend must immediately process every order request and, if any item is out of stock, respond exactly as specified below. Example SendOrderToMerchant out-of-stock response:- Returning ErrorCode: 1100 is required for proper flash sale out-of-stock handling.
- The error code can be changed via Global-e configuration, but 1100 is the default.
- Can also be triggered via pattern matching on the Message; requires Global-e configuration.
- For successful orders (stock is available), respond with your usual success response.