Core vs. Fashion Inventory: How to Plan the Right Mix as Your Brand Scales
How to Plan the Right Core vs. Fashion Inventory Mix as Your Brand Scales
If your inventory feels unpredictable, the issue often isn’t how much you’re buying — it’s what kind of inventory you’re holding.
As brands scale, planning core and fashion inventory the same way quietly increases risk. Core products drive steady, repeatable demand and stabilize cash flow, while fashion products create excitement but carry higher uncertainty and shorter selling windows. When the mix isn’t intentional, inventory dollars get tied up in slow-moving SKUs, demand signals get distorted, and markdown risk rises.
Healthy inventory planning separates these roles on purpose: funding core inventory first, tightly controlling fashion risk, and using open-to-buy to balance stability with momentum. When each category has clear expectations, inventory becomes more predictable — and growth becomes less stressful.
Keep reading to learn how to spot an imbalanced mix, decide where risk belongs in your assortment, and build guardrails that let creativity and profitability coexist.
Core vs. Fashion Inventory: How to Plan the Right Mix as Your Brand Scales
If your inventory feels unpredictable — some weeks you’re overstocked, other weeks you’re selling out — the issue often isn’t how much inventory you’re holding.
It’s what kind.
As brands scale, one of the most important — and often overlooked — decisions in inventory planning for growing product-based brands is how you balance core inventory versus fashion inventory. Treat them the same way, and inventory risk builds quietly through tied-up cash, margin erosion, and distorted demand signals. Plan them intentionally, and inventory starts supporting predictable sales instead of constant stress.
Before we go further, one quick clarification on language. When we talk about core and fashion, we’re not just talking about apparel. These are retail inventory planning concepts that apply across categories — beauty, wellness, CPG, home, accessories, and beyond.
Core inventory refers to products with steady, repeatable demand.
Fashion inventory refers to products driven by seasonality, trends, launches, or short-lived moments of interest.
The labels may change by category, but the planning principles stay the same.
This distinction often feels intuitive early on. As brands grow, it gets cloudier — and mistakes get more expensive.
How Inventory Decisions Actually Happen Early On
In the early days, most brands are built around a few flagship products.
Founders typically buy deeply into the hero item — the product they believe in most — and then layer in supporting products that feel like they should enhance the customer experience. Those adjacent items often make sense intuitively, but there’s usually very little data to confirm how they’ll actually sell.
Even in early-stage brands that already have a planner in place, buying is still heavily influenced by excitement and creative instinct. Teams hope the assortment resonates. Sometimes it does. Sometimes it doesn’t.
That’s normal. It’s often how brands find product–market fit in the first place.
The challenge is that this same approach becomes risky as the business scales.
Assortment Expansion Doesn’t Always Mean Demand Expansion
As brands grow, founders naturally want to expand their assortment.
Sometimes that means adding complementary products — items designed to enhance the hero product or complete the customer experience. Other times, it shows up as new variations of the flagship itself: additional colors, patterns, flavors, scents, sizes, or formats.
On paper, this often feels like growth. More SKUs should mean more demand.
In reality, that’s rarely how customers behave.
Each additional SKU doesn’t create exponential demand — it often just redistributes it. You might attract new customers with additional items, but your existing customers aren’t always buying more; they’re choosing between more options.
We regularly see situations where:
New variations dilute performance of proven SKUs (Sales shift across colors, flavors, or formats without increasing total units sold.)
Assortment expansion adds complexity without adding volume (More SKUs, but total demand for the category stays flat.)
Complementary products split the same customer spend (Customers choose between items instead of adding to cart value.)
Inventory investment shifts from velocity to optionality (Capital gets tied up in “nice-to-have” options that sell slower than expected.)
Without intentional planning, assortment expansion can increase inventory risk without meaningfully increasing revenue.
And that risk compounds as the business scales.
What Changes as You Scale (and Why It Matters)
As brands grow, revenue should increase — and sometimes that provides more financial flexibility. But inventory decisions also become more complex and more expensive at the same time.
We see this show up as:
Higher SKU counts as assortments expand
Vendor minimums and setup costs that increase with complexity
Higher storage and fulfillment costs as inventory volume increases
Greater markdown risk when products don’t sell at the velocity you planned
Forecast errors that are harder to absorb financially
At this stage, the question shifts.
It’s no longer just “Can we afford this inventory?”
It becomes “Where are we placing risk across the assortment?”
That’s where clearly separating core inventory from fashion inventory becomes essential to effective demand planning, healthy inventory turnover, and calmer decision-making.
Core Inventory: The Reliable Foundation (Not the Boring Stuff)
Core inventory is the dependable foundation of a retail business.
These are the products customers come back for again and again — regardless of trends, seasons, or what’s currently popular on social media. They form the backbone of predictable demand.
In apparel, these might be basics or proven bestsellers.
In other categories, core products could be:
A hero skincare formula or size that customers reorder
A best-selling supplement
A household essential that sells steadily year-round
They’re not quite so flashy — but they’re essential.
Core products tend to:
Drive consistent, repeatable sales
Be easier to forecast accurately
Tolerate higher weeks of supply (WOS) because they remain relevant longer
Stabilize overall inventory turnover
They also build customer trust. When shoppers know they can reliably find what they need, they form habits — and habits are what turn first-time buyers into loyal customers.
Predictability is why core inventory generally carries lower risk.
Core doesn’t mean unchanging — but it does mean proven. Even when core products evolve through new variations or updates, they earn their place through repeatable demand, not optimism. Without that distinction, brands often overfund choice instead of performance.
Fashion Inventory: The Spark (and the Risk)
Fashion inventory plays a very different role.
Outside of apparel, fashion might look like:
Limited-edition flavors or scents
Trend-driven packaging updates
Influencer collaborations
Seasonal launches
New products designed to create urgency
Fashion inventory creates excitement. It’s what makes customers stop scrolling and think, “I need that now.”
When it works, fashion can drive strong margins and meaningful growth — especially as product lifecycles have shortened and newness carries more weight than ever.
But fashion also comes with more uncertainty, and more financial pressure.
Even unproven products still come with real constraints: vendor minimums, production commitments, and the expectation that inventory will move through its lifecycle. Unlike core products, fashion items often need to sell through within a limited window — whether demand materializes or not.
That means inventory dollars invested in fashion don’t always convert to profit at the same rate as core. In some cases, they don’t convert to profit at all.
Trends fade. Interest shifts. What feels relevant today may feel dated quickly. That’s why fashion inventory needs to be planned differently — with:
Lower initial weeks-of-supply targets
Tighter inventory buys
Faster performance check-ins
Clear expectations around risk and exit
Fashion should create momentum for your product-based business — not erode margin or become a warehouse problem.
How Core and Fashion Inventory Distribute Risk
Rather than thinking about inventory in terms of how products look or how exciting they feel, it’s more useful to think about how much financial exposure each product creates.
In inventory planning, risk shows up as:
How long cash is tied up before it returns
How much margin is required to sell through inventory
How sensitive demand is to timing, trends, or context
Core and fashion inventory sit in very different places across those dimensions.
Core inventory: the foundation
Core inventory forms the base of your inventory risk profile.
These products:
Represent the largest share of inventory investment
Carry the most predictable, repeatable demand
Can tolerate deeper inventory coverage without the same downside
Support steady, reliable inventory turnover
Because demand is proven and long-lived, cash invested in core inventory is more likely to return — and return on schedule. That reliability allows brands to plan confidently, replenish consistently, and avoid inventory fire drills.
Fashion inventory: controlled risk on top
Fashion inventory sits above core in the risk stack.
These products:
Sell within shorter, less predictable windows
Depend on trends, launches, or seasonal relevance
Require tighter weeks-of-supply targets
Need faster read-through and earlier decision points
Fashion inventory isn’t meant to carry the business. It’s a deliberate risk — one that can drive excitement and growth, but only when its financial exposure is clearly understood and intentionally limited.
Every retail category has its own version of this structure. The products change — but the way cash, margin, and time interact stays the same.
When the Mix Is Off: A Real Example
We worked with a seasonal apparel brand that offered a wide variety of colors and prints. From the outside, the assortment felt exciting.
At the SKU level, it told a different story.
When we reviewed SKU productivity and weeks of supply by option, we found certain colors carrying extremely high WOS with very little customer demand — while other options were simply cannibalizing sales from proven core styles. Inventory dollars were concentrated where customers weren’t choosing.
After a detailed assortment analysis and SKU rationalization, the strategy shifted:
A smaller group of core styles and colors were carried consistently
Seasonal options were treated as limited, higher-risk fashion plays designed to drive urgency
Newness was bought tighter, with clearer performance expectations
The result:
More sales with less inventory spend
Better vendor costing and margin
Healthier inventory turnover
Far fewer end-of-season headaches
This is usually the moment teams realize the issue isn’t creativity — it’s risk concentration.
Signs Your Core vs. Fashion Mix Needs Attention
You may be under-investing in core if:
Bestsellers are frequently out of stock
Revenue feels harder to predict
You rely heavily on new launches to hit sales goals
You may be over-investing in fashion if:
Markdowns are a regular end-of-season ritual
Inventory turnover is slowing
Cash is tied up in slow-moving SKUs
Neither is “bad.” Both are signals worth listening to.
What a Healthy Mix Often Looks Like
There’s no universal ratio, but for many scaling brands, a healthy starting point is:
60–80% core inventory
20–40% fashion inventory
More fashion-forward brands may accept higher risk. More essentials-driven brands may lean more heavily into core. The right mix depends on your customer — finding the right ratio gets easier with expert demand planners on your team.
How This Shows Up in Open-to-Buy Planning
Your open-to-buy (OTB) process should reflect the different jobs these categories perform.
In practice, that means:
Funding core replenishment first
Protecting minimum inventory levels for bestsellers
Allocating remaining dollars to fashion inventory
Limiting SKU count through intentional assortment planning
Leaving room for in-season adjustments
This structure allows experimentation without destabilizing the business.
Core inventory creates stability. Fashion inventory creates momentum.
When each is planned intentionally — with different weeks of supply, different risk tolerance, and different expectations — inventory becomes more predictable, cash feels less strained, and growth feels far less chaotic.
Inventory planning becomes a process you can trust, grounded in real demand and refined with every buying cycle so you’re not continuously stuck reacting to inventory issues.
If this feels like a shift from how you’ve planned in the past, that’s normal. Most brands don’t need more data — they need clearer categories and better guardrails. This is often the moment inventory planning moves from instinct-led to structure-led, without losing creativity in the process.
You don’t have to get the mix perfect. You just have to be honest about what each product is meant to do for the business.
When that clarity is in place, decisions get easier. Risk becomes visible earlier. And inventory starts supporting growth instead of quietly working against it.
Want a Second Set of Eyes on Your Core vs Fashion Inventory Plan?
If you’re not sure whether your core and fashion inventory are working together — or creating risk — you’re not alone. This is one of the most common challenges we see as product-based brands grow.
At Boon, we partner with founders and planning teams to build inventory planning and demand planning frameworks that fit how your business actually operates. That includes setting realistic weeks-of-supply targets, designing open-to-buy plans, and helping teams make smarter inventory decisions without overcomplicating the process.
If it would be helpful to talk through your assortment, inventory mix, or planning approach, we’d love to support you.
→ Book a call with the Boon inventory planning team.
