Amazon MCF Now Puts Prime on Your Own Website. Is 15–25% Off Fulfillment Worth the Lock-In?

Picture two product pages for the same $24 phone case. (This is an example, not a real store.) One says "Ships in 3 to 5 business days." The other shows the blue Prime logo and "FREE delivery Thursday." Until last month, the second version lived on Amazon, or on sites that handed their checkout to Amazon.

That changed on September 24, 2026. Amazon's press release on Prime delivery for merchant websites announced two things for sellers who use Multi-Channel Fulfillment (MCF). MCF is the Amazon service that ships orders from any sales channel out of the stock you already keep in Amazon's warehouses. Sellers can now show the Prime badge and Prime delivery on their own websites at no added cost. And a new MCF Preferred Pricing program cuts MCF fees by 15–25% during a merchant's first six months.

For most sellers already on FBA (Fulfillment by Amazon, where Amazon stores your stock and ships your Amazon orders), this is worth turning on. It is not worth moving everything onto. The badge can lift sales and the discount saves cash, yet both pull more of your website's delivery promise into Amazon's buildings. This post covers what changed, what one order costs under each option, and how to use MCF without betting all your stock on one pool that Amazon controls.

What Amazon announced

According to Amazon's announcement of Prime delivery on merchant websites, the new pieces are:

• Prime delivery on your site. Once enabled, a Prime badge and delivery estimate appear on your product pages. Amazon verifies the shopper's Prime membership and ships the order from your inventory in its network.
• No change to your checkout. Amazon says merchants do not need to change payment processing, order management or store policies, and order confirmation and tracking come from the merchant.
• MCF Preferred Pricing. FBA sellers get a discount on MCF fulfillment fees combined with FBA credits on each unit shipped. It covers orders from your own site, other marketplaces and social channels. Enrollment is one click in Seller Central, with no contract.
• Early results. Among early adopters, more than 40% of eligible orders shipped with Prime delivery on average.
• Where it works. U.S. only. It is live through the Amazon MCF and Buy with Prime app for Shopify and the Selling Partner API, with more integration partners listed as coming soon.

The Prime delivery page on Amazon Supply Chain Services adds the operational detail. Shoppers do not log in to Amazon. Membership is checked after the order using details like email and shipping address. If Amazon cannot verify a shopper, that person gets a one-time free upgrade to Prime speed, then standard MCF speed on later orders. Fulfillment rates are "at parity with MCF Standard at launch," while storage fees and the 3.5% fuel and logistics surcharge still apply. Note the words "at launch." They describe today's price, not a promise about next year's.

MCF Prime delivery vs. Buy with Prime

Amazon has offered Prime on outside sites since Buy with Prime, which routes checkout through Amazon. The new option is lighter. The table compares them, using Amazon's Buy with Prime pricing page and the MCF Prime page.

For a brand with its own Shopify checkout, the MCF version removes the two biggest objections to Buy with Prime: the extra 3% and handing checkout to Amazon.

What a 1 lb order costs: worked example

Amazon prices fulfillment by size tier, a bucket set by a product's dimensions and weight. Small standard is the tier for small, light items such as a phone case or a paperback. Take one product in that tier weighing 12–16 oz, the heaviest band in it. It ships one unit per order at standard speed.

The MCF rate card effective June 1, 2026 lists $8.66 for this item on a 1-unit order, with the 3.5% fuel and logistics surcharge on top. The MCF with Prime table uses the same numbers. Holiday peak fees apply from October 15, 2026 to January 14, 2027. Amazon's Seller Central notice on 2026 holiday fees puts the average increase at $0.32 per unit across FBA, MCF and Buy with Prime. Supply Chain Dive's summary of the 2026 peak fees confirms the dates and that the surcharge stacks on top.

Amazon publishes only the average peak increase in that notice, so the peak column below assumes +$0.32. Check your own tier in Seller Central. The 3PL columns are a hypothetical quote from a third-party logistics company (3PL), an outside warehouse that stores and ships for you. It assumes $3.00 to pick the item off the shelf and pack it, $0.40 for packaging, $6.00 postage for a 1 lb ground parcel and a $0.40 carrier holiday surcharge. Replace these with your own quote.

At 1,000 direct orders a month, MCF at list saves $440 a month against this 3PL quote ($9.40 − $8.96 = $0.44 per order). With Preferred Pricing at 15% off, the gap grows to $1.78 per order, or $1,780 a month. Over the six-month window that is $10,680. Then it drops back to $440.

The rate card describes Preferred Pricing as up to 15% off MCF fees plus up to $1 in FBA credits per MCF unit. FBA credits are money off your future FBA fee bill, not cash off this order. On this item, 15% is $1.30. Add a full $1 credit and the combined value is about $2.30, roughly 27% of list. So a good share of the headline range comes from credits, and you should treat them as a rebate.

Three costs sit outside the table:

• Storage. MCF storage follows FBA rates: $0.78 per cubic foot per month from January to September and $2.40 from October to December for standard-size goods. A 0.047 cu ft unit costs about $0.04 a month off-peak and $0.11 a month in Q4.
• Returns. MCF charges a $3.55 return processing fee for this tier. Your 3PL's returns fee may be higher or lower, so compare them directly.
• Walmart orders after January 14, 2027. Walmart does not allow Amazon-branded delivery vans on its orders, so you must block Amazon Logistics, Amazon's own delivery fleet. The 5% surcharge for that block is waived for MCF orders, including Walmart, until then. Afterward it adds about $0.43 to this item's fee.

For a deeper breakdown of the fee lines, see our 2026 FBA fulfillment fee breakdown. To check which tier a SKU falls into before you model it, use the FBA size tier explorer. To get the 3PL side of the comparison, the shipping cost estimator helps you estimate postage.

The upside

• More first-time buyers. Amazon says 40% of Prime members are more likely to make a first purchase from a site showing the Prime logo, and 50% are more likely to buy again from sites offering Prime delivery. These are Amazon's numbers, so test them on your own traffic. For a brand shoppers have never heard of, the direction is plausible.
• Cheaper shipping on light orders of one item, especially during the six-month discount.
• One stock pool for every channel. Amazon reports that sellers using both MCF and FBA cut out-of-stock rates by 19% and sold through their stock 12% faster on average.
• You keep the customer. Unlike Buy with Prime, checkout, email, returns policy and customer service stay yours.
• Blank boxes by default. Amazon's guide to unbranded MCF packaging says blank packaging is automatic at no extra fee. U.S. items over 56 inches on the longest side or 49.9 lb are excluded.

The lock-in: seven risks to price in

1. Capacity limits decide your website's stock. MCF draws from FBA inventory, so Amazon's limits on how much you can send in now cap your website too. Those limits depend partly on your IPI score (Inventory Performance Index), Amazon's grade for how well you manage FBA stock. If Amazon tightens your limits for October to December, your Shopify store runs short as well. Our IPI score and storage limits guide covers how those limits are set.
2. Direct orders can stock you out on Amazon. A viral TikTok or a Shopify promo pulls from the same units your Amazon listing needs. You could lose the Buy Box (the Add to Cart button, which goes to one seller when several offer the same item) because your own site sold through.
3. Peak pricing is Amazon's to set. Peak fees, the fuel surcharge and Q4 storage all move on Amazon's calendar. "Parity at launch" can change later.
4. The discount ends. Preferred Pricing covers the first six months. If MCF only wins because of the discount, you are signing up for a price increase in month seven.
5. Stranded stock. Getting inventory back out of FBA means removal fees and waiting. A pallet at a 3PL can move in days. FBA stock is slow and costly to move when a channel shifts.
6. Your delivery promise depends on Amazon. The Prime badge on your site is a promise Amazon keeps or breaks. Amazon reports 96% on-time delivery for MCF, but if your account has a listing or compliance problem, the brand you built to reduce Amazon dependence goes down with it. We covered this pattern in why sellers grow more dependent on Amazon every year.
7. Returns and verification friction. Returns follow your policy but Amazon charges its return fee. Shoppers whose membership cannot be verified get Prime speed once, then standard speed, which can create "your site promised Prime" support tickets.

Walmart, eBay and TikTok Shop rules

Using one FBA pool for every channel only works if every channel allows it. This is what each platform's own pages say.

Note that Walmart runs its own competing service, Walmart Multichannel Solutions, which fulfills orders from other sites out of Walmart Fulfillment Services inventory. If Walmart is your second-largest channel, get a quote from it too.

MCF vs. 3PL vs. your own warehouse

If you are still deciding the base model, start with our FBA vs. FBM vs. 3PL decision framework and the 3PL vs. in-house fulfillment comparison.

The inventory allocation problem

Once FBA stock serves Amazon, Shopify, Walmart and TikTok Shop, "how many do we have?" becomes "how many can each channel sell?" Seller Central shows one number. Your Shopify store, your Walmart listing and your 3PL each show another. You need one stock count that every channel reads from, and a rule that decides where each order ships from. Treat FBA as one location with a reserve held back for Amazon, not as a bottomless pool.

In plain English: keep enough FBA stock for about three weeks of Amazon sales, and send a website or Walmart order to MCF only when there is stock above that reserve and MCF is the cheaper way to ship it.

For each non-Amazon order:
  amazon_reserve = Amazon daily velocity x days of cover (e.g. 21)
  fba_free       = FBA sellable - amazon_reserve - open MCF orders

  mcf_cost = MCF tier fee x 1.035
             + peak fee        (Oct 15 - Jan 14)
             + 5% AMZL block   (Walmart orders, after Jan 14, 2027)
  tpl_cost = 3PL pick/pack + packaging + postage for this zone

  if fba_free >= qty and mcf_cost <= tpl_cost + prime_value:
      route to MCF   (unbranded box; block AMZL if Walmart)
  elif 3PL on hand >= qty:
      route to 3PL
  else:
      route to own warehouse or hold, and alert

"Days of cover" is how many days of sales the reserve would last. The reserve protects your Amazon ranking from your own website. "prime_value" is the extra profit per order you have measured from the badge. Start it at zero and raise it once your test shows a lift.

Rules like this fail without warning when one channel's stock count runs a few minutes behind. The order routing bug that sends profit to the wrong warehouse shows how that happens. Nventory's order routing reads FBA, 3PL and warehouse stock together and picks a location for each order, and it links to Seller Central through the Amazon integration. For reorder timing when FBA serves several channels, the FBA vs. FBM inventory planning guide covers the forecasting side.

What to do this week

1. Price your 10 best-selling website products at MCF list, MCF peak and MCF with 15% off against your current 3PL or in-house cost. Keep only the SKUs where MCF wins at list, not just with the discount.
2. Turn on Prime delivery for half your product pages and compare their sales rate with the other half for four weeks.
3. Enroll in Preferred Pricing if you will ship MCF volume anyway. There is no contract. Note the start date so month seven does not surprise you.
4. Set an Amazon reserve in days of cover before any MCF orders go live, and check your FBA storage limits for October to December.
5. For Walmart orders, confirm blank boxes and the Amazon Logistics block are on, and add the 5% surcharge to your model from January 15, 2027.
6. Keep a second fulfillment path (3PL or your own stock) live with at least two weeks of inventory for your top sellers.
7. Book inbound shipments now. Amazon's Black Friday cutoffs start October 14 for AWD (Amazon Warehousing and Distribution, its bulk storage service) and October 21 to 28 for FBA shipments.

If MCF becomes one of two or three places you ship from, you can test per-order routing on the Free plan, which has unlimited orders and needs no card. Paid tiers are on the pricing page.