Overview

Amazon updated its Seller Fulfilled Prime (SFP) program in late 2023 to include on-time delivery as a formal eligibility requirement. This change means that sellers who fulfill their own Prime orders must consistently deliver items by the estimated delivery date or risk losing their SFP status. Understanding how Amazon calculates on-time delivery — and how promise extensions factor in — is essential for any seller participating in this program.

Key Points / What Sellers Need to Know

• On-time delivery is now an SFP eligibility metric — Starting October 1, 2023, Amazon introduced a minimum on-time delivery threshold that Seller Fulfilled Prime participants must meet to remain eligible for the program.
• Amazon generates the estimated delivery date — The delivery window customers see at checkout is calculated by Amazon based on your managed delivery time and other logistical factors. This is the date against which your performance is measured.
• Promise extensions may differ from your "Deliver by" date — Amazon sometimes adds extra time (called a "promise extension") to the customer-facing estimated delivery date to account for logistical slowdowns. When this happens, the date customers see is later than the "Deliver by" date shown in your Seller Central order details.
• Promise extensions are being scaled back — Amazon expects that as on-time delivery performance improves under the new requirements, promise extensions will be reserved only for major uncontrollable events such as hurricanes or significant snowstorms, rather than routine logistical delays.
• Your managed delivery time matters — This setting directly influences the estimated delivery date Amazon presents to buyers, so keeping it accurate is critical to meeting on-time delivery targets.

How On-Time Delivery Is Measured

On-time delivery tracks the percentage of items that arrive at the buyer's address on or before the estimated delivery date that Amazon generates at checkout. This estimated date incorporates your managed delivery time — the handling and transit window you configure in Seller Central — and often matches the "Deliver by" date visible on your order details page. However, in some cases Amazon adds a promise extension, giving customers a later expected arrival date than what you see internally. When a promise extension is applied, your effective deadline is more lenient because the customer-facing date is pushed out. When no promise extension exists, both dates are identical, and you must deliver by the date shown in your Seller Central orders.