FSN stands for Flipkart Serial Number. It is Flipkart's internal identifier for a product: one FSN per distinct item in the catalogue, whichever seller is offering it. If you sell on Amazon, the FSN is the direct counterpart of the ASIN. Sellers meet FSNs everywhere in Seller Hub: in the listings table, in ad campaigns, in the returns and SPF dashboards and in every report Flipkart exports. Knowing how FSN relates to the two other codes on a listing saves a lot of confusion.
How FSNs work
Flipkart's own developer documentation defines three identifiers that sit on top of each other:
- FSN: identifies the product. Flipkart defines a product within a sub-category (say, T-shirt or mobile) by a fixed set of attributes such as brand, model, colour and size, and issues an FSN for that combination. A blue medium and a blue large are two FSNs.
- Listing ID (LID): identifies your offer on that FSN, carrying your price, stock, dispatch time and fulfilment mode. Two sellers on the same FSN have two LIDs.
- SKU ID: your own code, which you supply when listing and which Flipkart maps to the LID. It is what you use in bulk price and stock uploads.
An FSN is a string of upper-case letters and digits, typically 16 characters, and you can see it in the product URL after "pid=" as well as in the listing details in Seller Hub. When you list a product that already exists in Flipkart's catalogue, you search for it and "latch" your offer onto its FSN, and Flipkart creates only a LID. When the product is new, Flipkart's catalogue team approves the listing and issues a fresh FSN; Quality Check can take a few days and rejections come back with attribute or image errors to fix. Variation families on Flipkart are handled at product level too, so a colour and size grid is a set of related FSNs that Flipkart groups on one page.
Worked example: a seller uploads a bulk price file with 300 rows and 40 of them fail. The errors show the file used FSNs in the SKU column. Because the SKU ID is the seller's own code and the FSN is Flipkart's, the two never match; re-exporting the listing report and copying the SKU column fixes it in one pass.
Why FSNs matter for sellers
Everything Flipkart measures is keyed to the FSN. Ad campaigns select products by FSN and report units and ROI per FSN. Ratings and reviews attach to the FSN, so latching onto an existing product means you inherit its rating, good or bad, and creating a duplicate FSN for a product that already exists splits reviews and is a catalogue-policy breach that Flipkart can merge or suppress. Returns, SPF claims and payment reconciliation all reference the order item's FSN, and the settlement report shows commission by FSN, which is how you check that Flipkart has categorised the product correctly. For multi-marketplace sellers a master sheet mapping SKU to FSN, ASIN and GTIN is the single most useful operations document.
How to manage FSNs well
- Search the catalogue before creating. Latch onto an existing FSN when the product is identical; create a new one only when it truly differs.
- Keep SKU IDs stable. Changing your SKU breaks the mapping to the LID and orphans stock and ads history.
- Check the FSN's category and vertical in the listing report; a wrong vertical changes commission and the rating benchmark used for seller tier.
- Run ads at FSN level. Campaign reports by FSN show which variant converts, which decides where to spend.
- Record FSNs on every SPF claim and support ticket. Flipkart support resolves faster with the order item ID and FSN than with a product name.
Blooprint sets up catalogues and FSN mapping for clients under Flipkart account management and catalogue and listing optimisation. The Flipkart seller fees guide shows how to read commission by FSN.