On Blinkit, Zepto and Swiggy Instamart, most brands sell on an inventory (B2B) model rather than a marketplace model: the platform buys your stock, owns it, and sells it to the consumer. The purchase order is the document that starts each of those transactions. It is raised by the platform's replenishment system or category manager, appears in the brand portal, and specifies the SKU list, quantity per SKU, agreed cost price, delivery location (mother warehouse or specific dark store), PO validity date and the appointment window for inwarding. Once you accept it, the PO becomes the reference for your invoice, the goods receipt note (GRN) and, eventually, your payment.
How it works
The typical cycle is:
- The platform's forecast for a store or region shows your SKU falling below its reorder point.
- A PO is generated, often automatically, and sent to your portal and email. POs usually carry a short validity, commonly 3 to 7 days, after which unshipped quantity lapses.
- You accept or partially accept, book an inwarding appointment and ship with the PO number on the invoice and every carton label.
- At the gate the platform counts and inspects. Accepted quantity is recorded on a GRN; rejections are noted with reasons.
- Payment runs on the agreed credit terms from GRN date, not from shipment date.
Worked example: Instamart raises PO #IM-88213 for 600 units of a ₹180 MRP snack at an agreed cost of ₹126 (a 30% margin to the platform). PO value is ₹75,600. You ship 600, 12 are rejected for damaged outer cartons, GRN shows 588 units and ₹74,088. That ₹74,088 is what you invoice and what enters the payment cycle. The 12 units come back at your cost or are written off, depending on your agreement.
None of the three platforms publishes standard PO validity days, credit terms or margin on a public help page as of September 2026; all of these are set in the brand agreement.
Why it matters for sellers
The PO is the only demand signal you get. Its size tells you how the platform's forecast rates your product; its frequency tells you whether you are gaining or losing store distribution. A brand that treats POs as routine paperwork ends up chasing rejections and short payments. A brand that reads them closely can spot a store cluster where velocity is rising and ask for wider listing before the competitor does.
How to manage it
- Set up a PO log: number, date, site, ordered, shipped, accepted, GRN date, invoice, payment due. Reconcile weekly.
- Never ship more than the PO or a different pack; excess is rejected and delays the whole consignment.
- Print the PO number, GTIN, batch and expiry on every carton; gate teams check these first.
- Raise short-payment or rejection disputes within the platform's window (check your agreement) with the GRN and photos attached.
- Watch PO size trends per SKU; a falling PO is an early warning that store-level sales or fill rate has slipped.
Blooprint's ex-Flipkart operations team handles PO acceptance, appointments and reconciliation under our quick commerce service. New to the channel? Start with how to sell on Blinkit, Zepto and Instamart.