When a product is almost sold out, customers do not suddenly want less.
They still want 3, 4, or 5 units. They just run into a cart that can only sell what is available right now.
That moment is where a lot of revenue disappears for Shopify merchants.
Most pre-order apps solve this with an all-or-nothing experience: either the customer buys what is in stock, or they pre-order everything. There is no clean way to do both in a single cart.
Today we are introducing Smart Cart Inventory Allocation - a feature that automatically splits cart quantities into in-stock purchases and pre-orders, based on real-time inventory. And yes - no other pre-order app does this.
Table of Contents
- The problem with low-stock shopping
- What Smart Cart Inventory Allocation is
- How the automatic cart split works
- Why this is unique (and why it matters)
- Getting started with K1 Pre-Order
The problem with low-stock shopping
Low inventory creates a very specific kind of friction:
- Customers want multiple units, but only 1-2 are available.
- The cart forces the customer to compromise, or to repeat the purchase in multiple steps.
- Merchants end up losing sales on their most popular products.
- When customers do place mixed orders, it is often unclear what ships now and what ships later.
The end result is predictable: lower conversion rate, lower average order value, and more support questions.
What Smart Cart Inventory Allocation is
Smart Cart Inventory Allocation is a cart experience that automatically creates clarity.
When a customer adds more units than are available, the cart splits that single line item into two line items:
- Regular purchase - the quantity that can ship now
- Pre-order - the remaining quantity that will ship later
The customer does not need to calculate anything. The merchant does not need to clean up orders later. The cart makes the split immediately, based on inventory.
How the automatic cart split works
Here is the simplest way to think about it:
- The cart checks how many units are available right now.
- If the customer adds a quantity within that number, nothing changes - it is a normal purchase.
- If the customer adds more than what is available, the cart automatically splits the quantity into “buy now” and “pre-order”.
For example, if you have 1 unit left and a customer adds 5, the cart will instantly show 1 regular purchase + 4 pre-order - in a single checkout, with zero extra steps.
That is the experience most merchants expect, but most pre-order apps do not support.
Why this is unique (and why it matters)
A lot of pre-order apps focus on the product page. That helps, but it does not solve what happens when customers change quantities in cart, or when inventory changes while a customer is shopping.
Smart Cart Inventory Allocation is different because it solves the problem where it actually happens - inside the cart.
Why this matters for merchants:
- Higher average cart value - customers can buy the maximum available now, and still reserve the rest.
- Less friction - no manual math, no confusing workarounds.
- Clear expectations - the cart clearly shows what ships now vs later.
- Better customer experience - customers feel like the store is helping them, not blocking them.
Getting started with K1 Pre-Order
If you are selling products that go out of stock, or you run launches where demand is higher than supply, Smart Cart Inventory Allocation is built for you.