ShippingCow3PL for Amazon Seller Fulfilled Prime (heavy items)
An Amazon SFP 3PL stores your inventory and ships your Prime orders, so you keep the Prime badge without using FBA. For Extra Large items Amazon wants a two-day delivery date on at least 25% of Prime page views and a five-day date on at least 60%, and weekend page views count again from October 18, 2026. Ask where the 3PL holds stock, whether it ships on a weekend day and what carton limits apply.
What Amazon sets for Seller Fulfilled Prime (checked Oct 13, 2026)
| Rule | What Amazon sets | What it means for a heavy item |
|---|---|---|
| Extra Large speed, from Jul 6, 2026 | A two-day delivery date on at least 25% of Prime page views (up from 15%) and a five-day date on at least 60%. No one-day share is listed for this tier | The shares count page views, not shipped orders, and they depend on where the stock sits and how your shipping template is built |
| Weekend page views, from Oct 18, 2026 | Weekend page views were left out of the speed metric through Oct 17, 2026 and count again from Oct 18. Weekend fulfillment was never suspended, only the scoring | A warehouse that does not ship on a weekend day can lower your share of fast delivery dates |
| 30-day trial | At least 100 Prime packages in 30 days, with on-time delivery of at least 93.5%, valid tracking of at least 99% and seller-cancelled orders below 0.5% | These are your account's numbers, so your 3PL's carrier scans and tracking uploads decide your trial |
| Handling time, from Jun 29, 2026 | Each seller-fulfilled SKU needs an accurate SKU-level handling time: turn on Automated Handling Time or keep SKU-specific times | Set it to what the warehouse really does with a heavy carton, not to what the listing would like |
What the speed percentages measure
Amazon scores the delivery date a Prime customer sees on your offer before buying. It does not score when the parcel ships or when it arrives. The date Amazon can promise comes from your shipping template: ZIP-level regions, cut-off times, warehouse locations, carrier transit times and weekend shipping (Cahoot, Jun 23, 2026).
Amazon also sorts each product into a size tier, and the 25% and 60% shares belong to the Extra Large tier. A longest side of 96 in or more puts an item in Extra Large, and Amazon's other triggers include weight and length plus girth (ppc.land, May 26, 2026). Check your ASIN's tier in Seller Central before you plan around these numbers.
Stock placement: one warehouse is rarely enough, and more is not automatic
A ground parcel from one warehouse reaches a limited set of ZIP codes in two days, so a single location leaves the far zones on a longer date. Stock the SKU in the East, the West and the south-central US and Amazon has more ship-from points to quote from.
Adding locations does not help by itself (Cahoot, Jun 23, 2026). Each one needs the stock, a cut-off time, a carrier pickup and weekend days you can actually keep. Amazon is rolling out a per-ZIP delivery-promise estimate in Seller Central (SellerSprite, Aug 1, 2026), which is the way to test a stock split before you enroll.
Carton limits to design a heavy SFP parcel to
| Limit | Keep the packed carton at or under | What happens past it |
|---|---|---|
| Actual weight | 110 lb | UPS Large Package, billed at a 90 lb minimum (UPS rule since Jan 26, 2026) |
| Volume | 17,280 cubic in | UPS Large Package |
| Longest side | 96 in | UPS Large Package or FedEx Oversize |
| Length plus girth (length + 2 × width + 2 × height) | 130 in | UPS Large Package or FedEx Oversize |
| Volume, softer target | 10,368 cubic in | Additional Handling for size at UPS and FedEx |
Every parcel over 50 lb also pays Additional Handling for weight at UPS and FedEx. A carton inside all four main limits stays out of the Large Package and Oversize lines on every Prime order. Carrier rules from the UPS 2026 tariff and the FedEx 2026 schedule, as checked on this site on Sep 25, 2026.
Onboarding a heavy SKU for SFP
Check the account. You need a Professional selling account, a US default shipping address and a realistic route to 100 Prime packages inside the 30-day trial.
Check the carton against the limits above. If it is over, fix it in the packaging design before stock arrives, because a carton over a line pays that line on every order.
Find the ASIN's size tier in Seller Central. The 25% two-day and 60% five-day shares apply to Extra Large.
Decide where stock sits. Send the SKU to each warehouse you want Amazon to promise from, and write down each one's cut-off time, carrier pickup and weekend days.
Build the Prime shipping template: one region per warehouse, the cut-off time and the weekend days you can keep. Run Amazon's delivery-promise tool and read the share of fast dates it shows.
Connect orders and tracking. Agree how Amazon orders reach the warehouse system, how labels are bought and how tracking returns to Amazon, because valid tracking is a trial metric.
Run the 30-day trial. Check on-time delivery, valid tracking and cancellations every day, and keep the carrier scan record in case of a dispute.
After enrollment, read the weekly numbers. A weak week needs a cause and a fix within days.
Where ShippingCow fits
ShippingCow is a self-operated US 3PL for products that pack into one carton of 50 to 149 lb, best at 71 to 110 lb, with warehouses in New Brunswick NJ, Ontario CA and Missouri City TX. For Amazon SFP 3PL fulfillment services that gives a heavy SKU three places to sit, with stock split by where your Prime orders go.
You keep the Amazon account, the shipping template and the SFP metrics. We run the warehouse side. Weekend coverage is the first question to put to any 3PL, us included: which locations ship on a Saturday or Sunday, and when does the carrier pick up? Get the answer in writing before you start a trial.
SFP is the wrong route if you cannot reach 100 Prime packages in 30 days, if the product ships as three or more loose cartons, or if one carton is over 149 lb.
Sources
| Source | What we took from it |
|---|---|
| Amazon: Seller Fulfilled Prime | The 30-day trial, the Professional selling account and the US default shipping address |
| ppc.land: Amazon tightens Seller Fulfilled Prime speed rules starting July 6 | May 26, 2026. The Extra Large two-day share up from 15% to 25%, the five-day share of 60%, the size-tier triggers and weekends left out of the speed metric until Oct 17, 2026 |
| SellerSprite: Amazon Seller Fulfilled Prime 2026 | Aug 1, 2026. The same Extra Large shares, the Oct 17 end of the weekend grace period, the 93.5% on-time delivery rate and the per-ZIP delivery estimate |
| Cahoot: Amazon's July 2026 SFP speed changes | Jun 23, 2026. The metric counts the delivery date a Prime customer sees, built from ZIP-level template inputs, and more warehouses are not automatically the answer |
| Feedvisor: Seller Fulfilled Prime, what's changed | Jan 30, 2024. The trial figures of 100 Prime packages, 99% valid tracking and cancellations below 0.5%. This is the oldest source here, so confirm those three figures in Seller Central |
| Novadata: Amazon handling-time rule | May 30, 2026. The SKU-level handling-time rule that took effect Jun 29, 2026 |
| UPS 2026 Tariff and Terms of Service | UPS Additional Handling and Large Package rules, including the 2026 cubic and 110 lb triggers |
| FedEx: What is an Oversize Charge? | FedEx oversize lines, the 90 lb minimum, and where freight starts |
Rules as published or reported by the sources below, checked on Oct 13, 2026. Amazon changes Seller Fulfilled Prime rules often, so confirm them in Seller Central before you enroll.
Questions
What is an Amazon SFP 3PL? +
A third-party logistics provider that stores your inventory and ships your Prime orders, so you keep the Prime badge without using FBA. You keep the Amazon account, the shipping template and the SFP metrics. The 3PL runs the warehouse, the carrier handoff and the tracking scans.
Can my 3PL enroll me in Seller Fulfilled Prime? +
No. Enrollment and the 30-day trial belong to your Amazon seller account, and Amazon scores the trial on your Prime orders. A 3PL ships those orders and supplies the scans.
What delivery speed does Amazon require for Extra Large items? +
Since July 6, 2026, a two-day delivery date on at least 25% of Prime page views and a five-day date on at least 60%, up from 15% for the two-day share (ppc.land, May 26, 2026). Amazon's published shares for this tier list no one-day figure.
When do weekend page views count in the SFP speed metric? +
From October 18, 2026. Weekends were left out of the metric through October 17, but the program still expects weekend orders to be fulfilled (ppc.land, May 26, 2026; SellerSprite, Aug 1, 2026).
How many packages does the SFP trial need? +
The trial runs 30 days and needs at least 100 Prime packages, with on-time delivery of at least 93.5%, valid tracking of at least 99% and seller cancellations below 0.5%. Amazon's program page confirms the 30 days and the other figures come from Feedvisor (Jan 30, 2024), so confirm them in Seller Central.
What carton size keeps a heavy SFP parcel out of Large Package pricing? +
Pack at 110 lb or less, 17,280 cubic inches or less, 96 in or less on the longest side and 130 in or less in length plus girth. Past any of those UPS adds a Large Package surcharge and a 90 lb minimum billable weight, and FedEx adds Oversize past the size limits.
Is SFP better than FBM for heavy items? +
SFP keeps the Prime badge, which a standard FBM listing does not carry, but it adds strict speed, tracking and weekend rules. A seller with low volume or no weekend shipping can be better off on FBM until volume is steady.
Amazon FBM for heavy items →Get the next one by email
One email a week, sent when there's a change. Unsubscribe any time.
Qualify, and your first pallet is on us: we truck it in and receive it. For customers who pass the Cost Audit. One pallet.
The first step