Keeping Dark Stores Stocked: Purchase Order Fill Rates on Blinkit, Zepto and Instamart

On Amazon, you send stock to a warehouse when you choose. Quick commerce works the other way round. On Blinkit, Zepto and Swiggy Instamart, the platform (or the seller entity it works with) decides what it needs, raises a purchase order (PO), and expects you to deliver the full quantity, on time, to its warehouse. From there, stock is split across hundreds of small dark stores.

How well you fulfil those POs, your fill rate, decides whether your products stay on the shelf in each city. Here's how the cycle works and how to keep it running.

How the PO cycle works

1. The platform forecasts demand for each product and city, based on recent sales and stock in its dark stores.
2. A PO is raised to you or your distributor, with quantities, the delivery warehouse, and a delivery window or expiry date.
3. You confirm the PO and book a delivery slot at the warehouse.
4. You deliver. The warehouse checks quantities, barcodes, packaging and remaining shelf life, and accepts or rejects units.
5. The warehouse supplies dark stores, and the platform pays you against the units accepted, on your agreed terms.

The platforms increasingly own the inventory they sell. Blinkit, for example, reported that about 80% of its quick commerce order value in July to September 2025 came from its own inventory. For brands, that means more selling through POs and less control over which products are stocked where.

What fill rate means

Fill rate = units accepted ÷ units ordered on the PO. A PO for 1,000 units where 850 are accepted is an 85% fill rate. Units count as missing if you deliver short, deliver late after the PO expires, or units are rejected at the dock.

Low fill rates hurt in three ways:

• Out-of-stock in dark stores: customers can't buy, and your product drops out of search and category listings in that area.
• Smaller or fewer future POs: platforms favour suppliers who deliver reliably.
• Penalties or charges, depending on your contract terms.

Why POs go unfilled

Shelf life: the quiet rejection reason

Food, personal care and other dated products usually need a minimum share of shelf life left when they reach the warehouse. Old batches sent to clear stock are a common cause of rejections. Check the shelf-life rule for each category in your platform agreement, and allocate your freshest stock to quick commerce.

A weekly routine that keeps fill rates high

1. Monday: review last week's POs by platform: ordered, delivered, accepted, rejected, fill rate.
2. List the misses and their causes (stock, slot, rejection, transport).
3. Check sell-through by city to see which products and warehouses will reorder soon.
4. Align production and dispatch to expected POs, not just to last month's orders.
5. Daily: check the portals for new POs, confirm them and book slots the same day.

Rationalise your range for quick commerce

Dark stores are small, and platforms keep only products that sell. Rather than listing your whole catalogue, focus quick commerce on your fastest movers in pack sizes that suit instant delivery, and keep them reliably in stock. A smaller range you can always fill beats a large range with frequent gaps. Our quick commerce guide covers getting listed in the first place.