Amazon's Fulfilled by Merchant Rules Are Tightening: What UK Sellers Need to Know Before September 

Every seller who fulfills their own Amazon orders knows the feeling: the order comes in, the clock starts, and somewhere between picking, packing and handing the parcel to a carrier, that clock stops being forgiving. From this summer, it gets less forgiving still. Amazon has confirmed a run of changes to its Fulfilled by Merchant (FBM) requirements for the UK store, tightening delivery, handling time and Amazon Business standards between July and October 2026. 

The On-Time Delivery Rate Isn't New, But the Stakes Are Real 

UK sellers have been expected to maintain a 90 percent On-Time Delivery Rate (OTDR) since September 16, 2025. Amazon started publishing the metric on the Account Health dashboard that month, sent improvement warnings from October 16, 2025, and confirmed that no enforcement action would apply before February 2, 2026. None of that is new. What Amazon has restated in its June 2026 update is what happens if you miss the bar: depending on performance, you may face anything from deactivation of individual listings to restrictions on listing new FBM products. It is a targeted, per-listing risk rather than a blanket, account-wide one, but it is a real one. 

Your Handling Time Buffer Is About to Disappear 

From July 15, 2026, the account-level default handling time on Amazon.co.uk will only offer 0-day and 1-day options. Any account still set to a two-day default will be automatically switched to one day, although a longer handling time can still be set at individual SKU level. From September 1, 2026, Amazon will automatically enable Automated Handling Time on any listing where the stated handling time has been at least a day slower than actual shipping performance for more than 30 days. In practice, that means any padding built into your handling times as a safety net gets removed for you, whether you have prepared for it or not. 

A New Clock for Business Customers 

If you supply Amazon Business customers, a separate standard applies from September 30, 2026: at least 90 percent of business deliveries must arrive within the customer's stated operating hours. Sellers who fall short will be notified and given a month to improve. If performance has not recovered by October 30, 2026, affected listings may be deactivated for business customers specifically. Amazon defines this metric as covering FBM shipments to Business customers only, so it is tracked separately from consumer OTDR and is worth watching as its own line item rather than assuming a good OTDR score covers it. 

What to Do Before the Deadlines Hit 

Start with your Account Health dashboard: check your current OTDR standing and identify any SKUs where the stated handling time is padded well beyond how fast you actually dispatch. Confirm your carriers and pick-pack process can consistently support a one-day handling promise before July 15, since that is when the cushion disappears for most accounts. If Amazon Business orders are a meaningful part of your sales, begin tracking your Business Hour Delivery Rate now rather than waiting for the September 30 deadline to arrive. None of this requires a different way of working, just an honest look at how fast you are actually shipping versus what your listings promise. 

Key Dates at a Glance 

Frequently Asked Questions 

Do I need to do anything if I already meet the 90 percent OTDR requirement? 

No. The requirement itself has not changed, only the reminder that Amazon is holding sellers to it. If you are already compliant, the main thing to watch is the new handling time and Business Hour Delivery Rate changes rather than OTDR itself. 

I already use Automated Handling Time. Does any of this affect me? 

Not much. Amazon's own tools, Automated Handling Time, Shipping Settings Automation and Buy Shipping, already keep correctly fulfilled orders from counting against OTDR or the Business Hour Delivery Rate, so sellers using all three are in a strong position ahead of these dates. 

Does the Business Hour Delivery Rate affect my consumer orders? 

No. Amazon defines it as the percentage of FBM shipments delivered to Amazon Business customers within their operating hours, so it only applies to orders sold to Amazon Business customers and is tracked separately from consumer OTDR. 

Helm WMS gives warehouse teams that visibility as standard, so dispatch times reflect reality rather than a setting nobody has checked in months. If you would like a hand working out where you stand against these changes, get in touch with the Helm WMS team.