What Is a SKU (Stock Keeping Unit)?

A SKU (stock keeping unit) is a code that a retailer or organisation defines to identify a distinct product type - a specific model, size, colour, or variant - for inventory tracking. Every interchangeable unit of the same product shares the same SKU; the moment a variant matters enough to count separately, it gets its own. That makes the SKU the opposite of an asset ID, which identifies one individual unit rather than a type.

How SKUs are structured

There is no global SKU standard - each organisation invents its own scheme, which is the point. A common pattern is short segments running from general to specific:

CBL-XLR-10M-BLK

Category (cable), type (XLR), length (10 m), colour (black). Anyone in the stockroom can decode it at a glance, and sorting by SKU groups related items naturally. The same logic applies whether the stock is retail merchandise, event equipment consumables like gaffer tape and batteries, or spare strings and cables behind a fleet of musical instruments.

Two habits keep a scheme healthy: encode only stable attributes of the product (never a shelf location or supplier, both of which change), and never reuse a retired SKU - historical orders and reports still point at it.

SKU vs serial number vs asset ID

The three codes are routinely confused because all of them end up printed near each other:

• SKU - identifies the type. Assigned by you. Every unit of the same product shares it. Answers “how many of these do we have?”
• Serial number - identifies the unit. Assigned by the manufacturer. Answers “which exact one is this?” for warranty and theft purposes.
• Asset ID - also identifies the unit, but assigned by you, in your format, for your register.

A barcode, RFID tag, or NFC chip is none of these - it is just a carrier that can encode any of them. Retail barcodes usually encode a standards-body product number, which is again separate from your internal SKU.

Where SKUs fit in asset management

Asset registers mostly track individual units, so SKUs enter the picture wherever items are interchangeable: consumables and restockable stock. Tape, gloves, batteries, cable ties, printer toner - nobody tracks which roll of tape someone took, only how many remain. The SKU is the unit of counting, and reorder logic hangs off it: a target stock level, a reorder point, a supplier, a unit price. In AMPthilly, consumable assets carry a per-asset SKU together with unit price, minimum order quantity, target stock, and reorder point, so purchase orders are raised against the same codes the stockroom counts in.

Common mistakes with SKUs

• Adopting supplier SKUs as your own. Change supplier and your entire history fractures; two suppliers can also collide on the same code.
• Overloading meaning. A SKU that encodes warehouse aisle, season, and buyer initials goes stale the first time anything is reorganised.
• One SKU for things that are not interchangeable. If the 5 m and 10 m cables share a SKU, every count is wrong in a way no one can see.
• Ambiguous characters. O/0 and I/1 cause silent mispicks; most schemes ban them outright.

Related terms

• Asset ID - your own per-unit identifier, the SKU’s individual counterpart
• Equipment Nameplate - the manufacturer’s plate carrying model and serial data
• RFID - radio tags that can carry a SKU or unit ID without line of sight
• NFC - tap-to-read tags scannable with a smartphone
• GPS Asset Tracking - live location tracking for individual high-value assets