What is the full form of SKU?

SKU stands for stock keeping unit. It is the code a seller gives each distinct item it stocks, down to the variant, so a blue kurta in size M has a different SKU from the same kurta in size L. In a warehouse, the SKU is what receiving, putaway, picking and stock counts are recorded against.

What is a SKU, with an example?

A SKU is your own code for one sellable variant. For example, ACME-KURTA-104-BLU-M could mean brand ACME, kurta, style 104, blue, size M. The same kurta in size L would be ACME-KURTA-104-BLU-L. Each SKU has its own stock count, so the warehouse and every channel know exactly which variant is available.

What is the difference between SKU and ASIN, FNSKU and FSN?

Your SKU is your own code. An ASIN is Amazon's 10-character catalogue ID, generated automatically; your seller SKU sits on your offer for it. For FBA stock, Amazon requires each unit to carry a label with a product identifier specific to its fulfilment services, which sellers call the FNSKU. An FSN is Flipkart's catalogue ID; your listing on it has a listing ID mapped to your SKU ID.

What is a SKU ID on Meesho or Flipkart, and how do you create one?

It is your own code for each product variant, entered when you list it. Flipkart's seller documentation maps each listing ID to the seller's SKU ID. For Meesho, follow its supplier panel's current help. Create it with the same pattern you use everywhere, so one internal SKU maps to every listing, and check each platform's current help for format rules.

How do you create SKU codes for clothing or cosmetics?

Pick a fixed pattern from the general to the specific. For clothing: brand–category–style–colour–size, such as ACME-KURTA-104-BLU-M. For cosmetics: brand–line–product–shade–pack size, such as ACME-LIP-07-RED-4G. Use capitals, numbers and hyphens only, keep it short, never encode price or batch, and never reuse a retired code.

What is the difference between SKU, barcode, UPC and EAN?

A SKU is your internal code, which you design. A barcode is the printed symbol a scanner reads. UPC and EAN are GTINs, product numbers issued by GS1: GS1 calls GTIN-12 the UPC, used mostly in North America, and GTIN-13 the EAN, used mostly elsewhere. A product usually has one GTIN everywhere, while each seller sets its own SKU.

Is the batch or lot number part of a SKU?

No. The SKU identifies what the product is; the batch or lot number identifies when and in which run it was made, and changes with every production run. Keep the SKU fixed and record batch and expiry separately at receipt, so you can pick by expiry and trace a recall. See batch and lot tracking.

How do you map one internal SKU to Amazon and Flipkart listings?

Keep one mapping table: your internal SKU, then each channel's IDs, such as the Amazon seller SKU and ASIN, and the Flipkart SKU ID and listing ID. The simplest route is to use your internal SKU as the seller SKU on each marketplace, since both let you set it. Map combos to their component SKUs, and check the table whenever a listing is added or merged.

What is a SKU (stock keeping unit)?

A SKU (stock keeping unit) is a code a seller creates for each distinct product it stocks and sells, down to the variant: every size, colour, pack size or flavour gets its own SKU. It lets the warehouse and every sales channel count, pick and sell exactly the right item. SKUs are internal; the seller decides the format.

SKU is usually pronounced “skew” or spelled out. It is not a barcode: a barcode such as an EAN carries a GTIN issued by GS1, while the SKU is the seller’s own code.

How SKUs work in an Indian D2C or omnichannel warehouse

One product, one internal SKU per variant, and a map from that SKU to every channel’s own ID:

Create the SKU when the variant is set up, with a fixed pattern.
Label the stock. Units or bins carry a barcode the warehouse scans; the system links it to the SKU.
Map each channel’s ID (Amazon ASIN, Flipkart listing, Meesho SKU ID and so on) to the internal SKU.
Count and move stock by SKU: receiving on the GRN, putaway, picking and cycle counts all work by SKU and bin.
Sync stock by SKU. One sale on any channel reduces that SKU’s stock on all channels.

Identifiers compared

Identifier	Who creates it	What it identifies
Your SKU	You	Your own variant, across all channels
ASIN (Amazon)	Amazon, automatically	A product in Amazon’s catalogue; 10 characters, alphanumeric
FBA unit label (“FNSKU”)	Amazon	Your units in Amazon’s fulfilment centres; required on each FBA unit
Seller SKU on Amazon	You (Amazon creates one if you don’t)	Your offer for that ASIN; can’t be reused for two products
FSN (Flipkart)	Flipkart	A product in Flipkart’s catalogue
Listing ID (Flipkart)	Flipkart	Your listing of that product, mapped to your SKU ID
GTIN / EAN / UPC	GS1 issues it	The product’s barcode number: GTIN-13 (EAN) or GTIN-12 (UPC)
HSN code	GST tariff	A tax classification on the invoice, shared by many products

Example: building SKU codes for apparel. Use brand–category–style–colour–size: ACME-KURTA-104-BLU-M is the brand ACME’s kurta, style 104, blue, size M. A catalogue of 200 styles × 3 colours × 5 sizes is 3,000 SKUs. Sold on 4 channels, that is 12,000 channel listings whose stock has to stay in step. One unmapped listing is enough to oversell. The brand and figures are illustrative.

Common SKU mistakes

Reusing a retired SKU for a new product. Old orders, returns and reports then point to the wrong item.
Putting price or batch in the SKU. Prices change and batches come and go; the SKU must not. Track batches separately with batch and lot tracking.
Spaces, slashes and special characters. They break uploads and barcode scans. Use letters, numbers and hyphens.
Leading zeros. Spreadsheets drop them; 0104 becomes 104.
One SKU for a combo and its parts. A combo needs its own SKU that reduces each component’s stock.

SKU count = styles × colours × sizes (plus packs and combos). Example: 200 × 3 × 5 = 3,000.
Listings to keep in sync = SKUs × channels. Example: 3,000 × 4 = 12,000.
Sell-through by SKU = units sold ÷ units received, over a period.

SKUs in the Indian context

Amazon.in. Amazon says every product sold on Amazon.in gets an automatically generated ASIN, “different from a GTIN or SKU”, and that the seller assigns the SKU at listing; the same SKU can’t be assigned to two products, and Amazon creates one if the seller doesn’t. For FBA, its FAQ says each unit must carry a label with “a product identifier specific to Amazon Fulfillment Services”, printed from the seller account.
Flipkart. Flipkart’s seller API documentation says a product is identified by a Flipkart Serial Number (FSN), and a seller’s listing by a listing ID mapped to the seller’s SKU ID.
Barcodes. GS1 says GTIN-13, also called EAN, is a 13-digit number mostly used outside North America, and GTIN-12, also called UPC, a 12-digit number mostly used in North America. Amazon.in lets sellers without a barcode apply for a GTIN exemption, for example for private-label products.
HSN is a tax code. CBIC’s invoice rules list the HSN code of goods among the particulars of a GST tax invoice; how many digits are needed depends on the seller’s turnover. Many SKUs share one HSN code, so it can’t stand in for a SKU.

How Fretron CommerceOS handles SKUs

Fretron CommerceOS syncs inventory across channels. Sync is automatic but not instant, and there are no per-channel buffers. The warehouse team works the floor on a phone, without handheld hardware, and picking is scan-guided: bin, then item. There is no offline mode, and labels print from the web, not the phone.

Questions and answers

What is the full form of SKU?: SKU stands for stock keeping unit. It is the code a seller gives each distinct item it stocks, down to the variant, so a blue kurta in size M has a different SKU from the same kurta in size L. In a warehouse, the SKU is what receiving, putaway, picking and stock counts are recorded against.
What is a SKU, with an example?: A SKU is your own code for one sellable variant. For example, ACME-KURTA-104-BLU-M could mean brand ACME, kurta, style 104, blue, size M. The same kurta in size L would be ACME-KURTA-104-BLU-L. Each SKU has its own stock count, so the warehouse and every channel know exactly which variant is available.
What is the difference between SKU and ASIN, FNSKU and FSN?: Your SKU is your own code. An ASIN is Amazon's 10-character catalogue ID, generated automatically; your seller SKU sits on your offer for it. For FBA stock, Amazon requires each unit to carry a label with a product identifier specific to its fulfilment services, which sellers call the FNSKU. An FSN is Flipkart's catalogue ID; your listing on it has a listing ID mapped to your SKU ID.
What is a SKU ID on Meesho or Flipkart, and how do you create one?: It is your own code for each product variant, entered when you list it. Flipkart's seller documentation maps each listing ID to the seller's SKU ID. For Meesho, follow its supplier panel's current help. Create it with the same pattern you use everywhere, so one internal SKU maps to every listing, and check each platform's current help for format rules.
How do you create SKU codes for clothing or cosmetics?: Pick a fixed pattern from the general to the specific. For clothing: brand–category–style–colour–size, such as ACME-KURTA-104-BLU-M. For cosmetics: brand–line–product–shade–pack size, such as ACME-LIP-07-RED-4G. Use capitals, numbers and hyphens only, keep it short, never encode price or batch, and never reuse a retired code.
What is the difference between SKU, barcode, UPC and EAN?: A SKU is your internal code, which you design. A barcode is the printed symbol a scanner reads. UPC and EAN are GTINs, product numbers issued by GS1: GS1 calls GTIN-12 the UPC, used mostly in North America, and GTIN-13 the EAN, used mostly elsewhere. A product usually has one GTIN everywhere, while each seller sets its own SKU.
Is the batch or lot number part of a SKU?: No. The SKU identifies what the product is; the batch or lot number identifies when and in which run it was made, and changes with every production run. Keep the SKU fixed and record batch and expiry separately at receipt, so you can pick by expiry and trace a recall. See batch and lot tracking.
How do you map one internal SKU to Amazon and Flipkart listings?: Keep one mapping table: your internal SKU, then each channel's IDs, such as the Amazon seller SKU and ASIN, and the Flipkart SKU ID and listing ID. The simplest route is to use your internal SKU as the seller SKU on each marketplace, since both let you set it. Map combos to their component SKUs, and check the table whenever a listing is added or merged.

Batch and lot tracking
GRN (goods received note)
Overselling
Dark store
Backorder and OMS (order management system)
D2C (direct to consumer)
SKU rationalization: on the Commerce glossary hub
Kitting
Reorder point
Dead stock
Inventory turnover ratio
EAN and GTIN
UOM (unit of measure)
Serial number tracking

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Last reviewed: 5 November 2026 by Fretron.

Sources

How to list products on Amazon.in (ASIN, SKU, GTIN, GTIN exemption). Amazon.in. https://sell.amazon.in/sell-online/list-your-products (accessed 5 Nov 2026).
Fulfillment by Amazon: Frequently Asked Questions (unit labels). Amazon.in. https://sell.amazon.in/shipping-and-fulfillment/fulfillment-by-amazon/fba-faq (accessed 5 Nov 2026).
Flipkart Marketplace Seller Platform (Developer API v3.0 documentation). Flipkart. https://seller.flipkart.com/api-docs/FMPlatOverview.html (accessed 5 Nov 2026).
What is the difference between a GS1 GTIN, a barcode, an EAN and a UPC? GS1 GO Customer Service Portal, modified 30 Aug 2024. https://support.gs1.org/support/solutions/articles/43000734124-what-is-the-difference-between-a-gs1-gtin-a-barcode-an-ean-and-a-upc- (accessed 5 Nov 2026).
Invoice Rules: Tax Invoice (CGST Rules, 2017). CBIC. https://cbic-gst.gov.in/gst-invoice-rules.html (accessed 5 Nov 2026).