# What Is an SKU?

***

### A Guide to Stock Keeping Units

An **SKU** (pronounced "skew") stands for **Stock Keeping Unit**. It's a unique code you assign to every distinct item you stock. Different sizes, colors, or variations each get their own SKU.

Think of it as your internal product ID. You design the format, decide what it means, and use it to track what's on your shelves.

#### A quick example

Say you sell pens from one brand. They come in three colors (black, red, blue) and two tip sizes (0.5 mm, 0.7 mm). That's **six SKUs**:

* Black, 0.5 mm
* Black, 0.7 mm
* Red, 0.5 mm
* Red, 0.7 mm
* Blue, 0.5 mm
* Blue, 0.7 mm

Each variant sells at its own pace. A customer who wants a red 0.7 mm pen doesn't care that you have plenty of black 0.5 mm in stock. SKUs let you track each one separately, so when something starts running low you can see it and reorder before it's gone.

***

### SKU vs. Barcode vs. UPC

It's easy to mix these up since they often show up together on the same item. Here's how they're different:

* **SKU:** — your *internal* code. You create it and control the format. It only needs to make sense inside your business.
* **UPC** (Universal Product Code) — a *standardized* 12-digit number issued by [GS1](https://www.gs1us.org/). It's the same across every retailer that sells the product.
* **Barcode** — a visual format (those black lines) that encodes a number. Both SKUs and UPCs can be printed as barcodes for scanning.

{% hint style="success" %}
In short: a **UPC** is universal, an **SKU** is yours, and a **barcode** is just how either one gets scanned.
{% endhint %}

***

### How to build an SKU system

Good SKUs are short, readable at a glance, and follow a consistent pattern. We recommend encoding the attributes that matter most to your business — brand, category, color, size, and so on — into a structured code.

Using the pen example, you might decide on a 6-character format:

```
A - BLK - 05
│   │     │
│   │     └── Tip size (05 = 0.5 mm)
│   └──────── Color (BLK = black)
└──────────── Brand "A"
```

* A black 0.5 mm pen becomes **A-BLK-05**.
* A blue 0.7 mm pen becomes **A-BLU-07**.

Once you've set the pattern, anyone on your team can look at a code and know what the item is.

***

#### A few rules of thumb

* **Keep it short.** 8–12 characters is a sweet spot. Long codes = harder to scan visually and easier to make typos.
* **Start with letters, not zeros.** Leading zeros get dropped by Excel.
* **Avoid ambiguous characters.** O and 0, I and 1, L and 1 (pick one or the other).
* **Don't reuse old SKUs.** When a product is discontinued, retire its code.
* **Leave out things that change.** Prices go up, suppliers switch. Stick to attributes that stay the same for the life of the product.

***

### Why are SKUs so important?

Without SKUs, "we have 40 t-shirts" is the most you can say. With SKUs, you can answer the questions that actually drive a business:

* Which size and color is selling out fastest?
* What's been sitting on the shelf for six months?
* Which variant should I reorder this week, and how many?
* Where are we losing stock between deliveries and sales?

Tracking at the SKU level means you're working with real numbers instead of rough estimates.

{% hint style="success" icon="lychee" %}
It's also the foundation for everything else you'll want to do — setting reorder points, pulling sales reports, managing bundles, and moving stock between locations.
{% endhint %}

***

### Using SKUs in BoxHero

Every item in BoxHero carries an SKU. You can manage them however works for your business.

#### ➤ **If you already have SKUs**

When adding an item, enter your code in the SKU field.

* <mark style="color:$primary;">`Item List`</mark> > <mark style="color:$primary;">`+ Add Item`</mark> > <mark style="color:$primary;">`Item Details`</mark> > <mark style="color:$primary;">`SKU`</mark>.

Importing from Excel? Map your SKU column during bulk upload.

* <mark style="color:$primary;">`Data Center`</mark> > <mark style="color:$primary;">`Items`</mark> > <mark style="color:$primary;">`Import from Excel`</mark> > <mark style="color:$primary;">`Add via Excel`</mark>.

<figure><img src="/files/ZCwpPpzMSNTFLyorUFWG" alt=""><figcaption></figcaption></figure>

#### ➤ **If you don't have SKUs yet**

Hit <mark style="color:$primary;">`Generate`</mark> next to the SKU field and BoxHero will create one for you automatically. You can edit it later, or use <mark style="color:$primary;">`Update SKUs via Excel`</mark> to edit a batch all at once.

Either way, once SKUs are in place you can print them as barcode labels, scan them on mobile, and pull reports on specific items.

<figure><img src="/files/8Q4oMxKsxkCZB7Qn7ec6" alt=""><figcaption></figcaption></figure>

***

### Related Guides

{% content-ref url="/pages/p5pOBrvHV4pnja33mI1Q" %}
[Items](/docs/concepts/items.md)
{% endcontent-ref %}


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