Amazon announced on October 21 that Seller Fulfilled Prime eligibility in the UK store changes starting October 30. Products will be assessed in three tiers: standard-size, oversize, and extra-large.

The immediate change is measurement. Amazon will calculate existing requirements at product-tier level instead of account level. Two new requirements then become eligibility tests on January 6, 2027, after a grace period.

That leaves an eight-week testing window.

What Changes October 30

Amazon will assess weekend-supporting shipping methods, on-time shipment rate, Buy Shipping or Easy Ship usage, and cancellation rate separately for each size tier.

Your account-wide average stops being useful. A seller with strong standard-size performance and weak extra-large delivery now sees the problem in the tier where it occurs, which also means that tier has to be managed deliberately rather than hidden inside total volume.

The SFP dashboard now shows the percentage of standard-size customer page views displaying a one-day delivery date.

The 25% One-Day Display Test

Standard-size products need at least 25% of customer page views showing a delivery date within one day. Amazon measures from October 30 but does not use it for eligibility until January 6.

Read the wording carefully. This counts page views showing the promise, not the share of orders shipped within one day.

The displayed date depends on inventory location, cut-off time, customer postcode, carrier coverage, and Amazon's own promise logic. One seller replying to the announcement argued the displayed date sits partly outside seller control. That is anecdotal, but the operational concern holds: you control dispatch speed and carrier settings, not every date Amazon shows every shopper.

Use the dashboard as a diagnostic. Check performance by day of week, postcode coverage, and cut-off period. If the percentage drops on weekends or after a specific collection window, the fix is carrier coverage or handling configuration rather than warehouse labor.

Amazon's tighter handling-time rules for seller-fulfilled listings already affect the delivery date shoppers see. This metric adds another reason to keep those settings aligned with real capacity.

Extra-Large Products Get Carrier Flexibility

For extra-large products, Amazon will allow a logistics provider outside Buy Shipping or Easy Ship. Two conditions apply: Amazon must receive a valid tracking number, and the seller must maintain at least 97% on-time delivery on those orders.

This helps, because oversized freight often needs specialist carriers that do not fit Amazon's label-buying tools.

The freedom is conditional. Tracking integration and delivery performance become the proof that an outside carrier can support Prime.

Test the carrier now rather than in January. Run enough extra-large volume during the grace period to measure scan quality, missed appointments, and rural-postcode performance. A provider can be reliable in general and still fail Amazon's data requirements if events arrive late or use an unsupported status format.

How to Use the Grace Period

Export your SFP catalog and map each SKU to Amazon's new tier. Compare warehouse cut-off times, carrier collection schedules, and weekend capacity against the dashboard metrics.

For standard-size items, identify the postcodes and times where the one-day display disappears. For extra-large items, verify every tracking number reaches Amazon and delivery scans arrive on time. For oversize products, keep monitoring the existing tier-level requirements even though Amazon announced no new speed threshold there.

Review cancellation rate separately. A fast carrier cannot protect the badge if your inventory feed accepts orders you cannot fulfill.

Save weekly screenshots or exports during the grace period. If Amazon changes the displayed promise or a carrier's tracking integration fails, you will have a record of when the metric moved and what preceded it.

Amazon says it will update its Maintain Enrolment in Seller Fulfilled Prime policy on October 30. Compare that final text against the announcement before changing carrier contracts or service levels.