TL;DR: Amazon’s March 31, 2026 FNSKU labeling mandate is now in effect. Commingled inventory is no longer accepted. Canadian FBA sellers who haven’t completed the transition must relabel existing inventory before resubmission and establish an ongoing FNSKU labeling process for all future shipments.
The March 31 Deadline Is Behind Us — Here Is What Changed
As of April 1, 2026, Amazon’s fulfillment network no longer accepts inventory without FNSKU labels. The two changes that took effect on March 31, 2026 are now operational policy, not upcoming requirements:
- Commingled inventory (stickerless) is no longer permitted for resellers. Units that previously used manufacturer barcodes and were pooled with identical units from other sellers must now carry FNSKU labels before entering the fulfillment network.
- Mandatory FNSKU labeling applies to all reseller accounts. This extends the existing requirement for private label sellers to all resellers who previously relied on manufacturer barcodes.
These changes build on Amazon’s discontinuation of its internal prep services as of January 1, 2026. With Amazon no longer labeling inventory on behalf of sellers, the responsibility for compliant labeling now sits entirely with the seller or their prep partner before inventory ships to FBA.
What Happens to Inventory That Was Not Relabeled Before the Deadline
Sellers with existing non-compliant inventory have two main options:
Option 1: Request a removal order. Amazon will return the inventory to your designated address. From there, each unit can be relabeled with the correct FNSKU and resubmitted as a new inbound shipment. This is the most reliable path for sellers with significant non-compliant stock.
Option 2: Use Amazon’s labeling service (where still available). Amazon’s labeling service was discontinued for most categories as of January 1, 2026. Check your Seller Central account to confirm whether this option remains available for your product categories.
For most Canadian sellers, removal followed by third-party relabeling is the practical path forward.
The Ongoing Requirement: Every Unit Needs an FNSKU Label
The March 31 deadline was a transition point, not a one-time event. Going forward, FNSKU labeling is a permanent requirement for all inbound FBA shipments from resellers:
- Every unit must receive an FNSKU label before it ships to Amazon
- The FNSKU is specific to your seller account and ASIN — it cannot be shared across accounts
- Manufacturer barcodes are no longer accepted as a substitute for commingled inventory
- Products must be individually labeled, not just case-labeled
How Canadian Sellers Are Handling the Transition
For sellers shipping from outside Canada, FNSKU labeling at the source is often impractical. Factory-applied labels frequently use incorrect barcodes, incorrect placement, or incorrect formatting for Amazon’s scanners. The practical solution is to use a Canadian third-party prep centre to receive inventory and apply FNSKU labels before forwarding to Amazon’s fulfillment network.
Practical Steps for Canadian Sellers Right Now
Step 1: Audit your current inventory. Log in to Seller Central and identify any inventory that entered the network using manufacturer barcodes. Check inbound shipment history for shipments predating March 31 that used stickerless settings.
Step 2: Initiate removal orders for non-compliant stock. Removal orders take 7–30 days to process. The sooner you initiate, the sooner inventory is available for relabeling and resubmission.
Step 3: Establish a FNSKU labeling workflow for all new shipments. Whether labeling in-house or using a third-party prep centre, the process needs to be repeatable and quality-controlled. Every unit should be verified before it ships.
Step 4: Update your supplier instructions. Verify label placement, label size, and barcode format against Amazon’s packaging guidelines.
Step 5: Confirm prep centre capacity. With the March 31 deadline having just passed, many sellers are processing backlogs simultaneously. Confirm current turnaround times before shipping.
MoRo Prep: Ontario-Based FNSKU Relabeling for Canadian FBA Sellers
MoRo Prep’s facility in St. Thomas, Ontario provides FNSKU relabeling for Amazon FBA sellers. Located near YXU1 — Amazon’s St. Thomas fulfillment centre at 11884 Sunset Dr — the facility handles high-volume relabeling, returns processing, and removal order reprocessing. Contact MoRo Prep for current turnaround times and volume pricing.
For sellers who want to understand how Amazon’s decision to stop providing in-house labeling services created this requirement, see Amazon Stops Labeling Service 2026: Why You Need a Prep Center Now. For sellers who need ongoing relabeling as a planned operational tool — not just a one-time compliance fix — see Amazon Relabeling Services Canada.
FNSKU Label Specifications: Getting It Right the First Time
Amazon’s FNSKU label specifications are precise, and non-compliance at the unit level is one of the most common causes of FC processing holds. Here is what the current requirements look like in practice.
Label size must be 1″ × 2.625″ — this is the standard Avery 5160 format, which means most commercial label printers and office supply stock are already compatible. Label stock must be matte and opaque. Glossy stock creates scanner reflections that cause misreads at high-throughput FC scanning stations, and Amazon’s receiving teams will flag entire shipments when a pattern of scan failures emerges.
The barcode zone must be completely clear of text, logos, or any other printing, with a minimum 0.1″ margin around the barcode on all sides. Placement must be on the exterior of the unit packaging — not on a seam, hinge, or curved surface where the label can lift, crease, or distort the barcode geometry. The label must fully cover the manufacturer barcode, rendering the original completely unscannable once the FNSKU label is applied. Amazon’s scanners will read the first barcode they can resolve; if the manufacturer barcode is still legible underneath, the unit may be processed incorrectly.
For poly-bagged items, the label goes on the outside of the bag, not inside. A label visible through poly film is not compliant — the scanner reads surface reflectivity, and poly film introduces enough distortion to cause intermittent misreads even when the barcode underneath is technically correct.
These specifications apply whether you are labeling in-house or through a prep center. The practical difference is that a prep center running a dedicated print-and-apply station performs a verification scan on every unit before it is packed into a carton, catching label defects before they become FC problems.
What Happens When FNSKU Labels Fail at the Fulfillment Center
When Amazon’s FC scanner cannot read an FNSKU label, the unit enters a manual processing hold. The typical timeline before the unit is either resolved or flagged for return is 7 to 14 business days. During that entire window, the unit is unavailable for sale — it does not appear in your inventory, and it cannot fulfill orders.
Amazon may also issue a non-compliance fee of $0.50 to $2.00 per unit on shipments where labeling defects are identified. If the defect rate across a shipment is high enough to trigger a shipment-level flag, all units in that shipment are frozen pending review — not just the affected units.
The downstream consequences matter most for sellers operating on tight restock cycles. A 14-day hold on 500 units ahead of Prime Day or Q4 peak is not just a cash flow issue — it is a ranking issue. A stockout during peak demand suppresses both sales velocity and review accumulation. Amazon’s search algorithm treats velocity as a ranking signal, and recovering lost rank after a stockout event can take several weeks of normalized sales after inventory clears. One labeling error at the wrong time can cost more in lost organic rank than it costs in non-compliance fees.
Cost Comparison: In-House Labeling vs. Prep Center
In-house labeling appears cheaper on a per-label basis. The real cost structure looks different once you account for all inputs.
Hardware runs $150 to $400 for a label printer capable of producing barcode-quality output. Label stock runs approximately $0.02 to $0.05 per label. Labor is where the math changes: at a careful manual application rate of roughly 60 units per hour, labeling 1,000 units takes approximately 17 person-hours. At $20 per hour, that is $340 in labor for 1,000 units — $0.34 per unit — before accounting for printer downtime, reprints for rejected labels, and the time spent on verification checks. There is also no scan verification step in most in-house workflows, which means defects travel through to the FC undetected.
Professional prep center rates for FNSKU labeling typically run $0.35 to $0.55 per unit, with scan verification included and no capital equipment cost on your end. For sellers shipping fewer than 500 units at a time, in-house labeling can still make sense if the operation is well-run. For sellers scaling past 2,000 units per shipment, the cost difference between in-house and prep center is marginal — and the error rate at a professional facility with dedicated equipment and trained staff is measurably lower.
Building FNSKU Labeling Into Your Supply Chain Long-Term
There are three models sellers commonly use, ranked here by reliability and compliance consistency.
- Full prep center model. The factory ships product to the prep center. The prep center applies FNSKU labels, performs scan verification, and forwards compliant cartons to FBA. This is the highest-reliability option. It works regardless of the factory’s country of origin, requires no Amazon-specific training at the factory level, and keeps all compliance responsibility with a single accountable party.
- Hybrid model. The factory handles poly-bagging, bundling, and outer carton protection. The prep center receives the goods and applies FNSKU labels before forwarding to FBA. This divides the labor efficiently — the factory does what it already knows how to do, and the prep center handles the Amazon-specific compliance layer. For sellers who manufacture in countries with lower factory labor costs, this model often delivers the best combination of cost efficiency and compliance reliability.
- Factory-direct labeling. The factory applies FNSKU labels before shipping directly to FBA. This works only with factories that have dedicated Amazon labeling experience, calibrated equipment, and stable staff. It requires periodic quality audits to catch specification drift, and it places the compliance risk entirely on the factory’s execution.
Most sellers sourcing from overseas find that options one or two deliver meaningfully better compliance rates than option three. Amazon’s label specifications are precise, and factory staff turnover — common in high-volume manufacturing environments — introduces inconsistency that is difficult to detect until units are already inside the FC. Building a prep center into the workflow creates a consistent, auditable compliance checkpoint that does not vary with factory staffing changes.