Amazon FBA Fees Explained

Understanding Amazon FBA costs is critical to profitability. With the global Amazon marketplace generating £717 billion in revenue in 2025, thousands of sellers compete across multiple regions. FBA remains the dominant fulfilment method for many sellers, but fees eat directly into margins. They’ve increased significantly in 2026.

This guide breaks down the complete FBA fee structure, shows how to calculate your true cost per unit, explains the major 2026 changes, and provides practical strategies to minimise fees without compromising your Amazon presence.

FBA Fee Structure Overview

Amazon FBA fees fall into four main categories:

1. Carrier and inbound fees – Shipping your inventory to Amazon fulfilment centres
2. Fulfilment fees – Charged per unit sold, based on product size tier and weight
3. Storage fees – Monthly charges for inventory held in Amazon warehouses
4. Optional service fees – Labelling, preparation, returns processing, and removal

Each category compounds, making accurate calculation essential. A product that seems profitable at the sale price may become marginal once all fees are applied.

Fulfilment Fees Explained

Fulfilment fees are charged per unit sold and depend on your product’s size tier. Amazon categorises products into five size tiers:

• Small Standard – Items up to 2kg and meeting dimension limits
• Large Standard – Larger items up to 20kg
• Small Oversize – Items 2–5kg exceeding dimension limits
• Large Oversize – Items 5–20kg in oversized dimensions
• Special Oversize – Heavy or bulky items exceeding 20kg

UK Example: A Small Standard item (under 2kg) incurs a fulfilment fee of approximately £3.58 per unit sold. Compare this to self-fulfilment via Royal Mail or courier, which typically costs £4+ for equivalent service. FBA becomes competitive immediately for fast-moving products.

If you sell on Amazon.com as well, expect similar fee structures but in USD. Small Standard items in the US average around £3.40 per unit at current exchange rates. The principle is the same: right-sizing packaging is critical to cost control across all marketplaces.

These are variable costs, charged every time a unit sells. A product sold 100 times per month incurs 100 × fulfilment fee charges.

Monthly Storage Fees

Storage fees are charged monthly and represent a significant hidden cost. They are calculated by cubic feet of space occupied:

Standard-Size Products (UK):

• January–September: £0.87 per cubic foot per month
• October–December (peak season): £2.90 per cubic foot per month

Oversize Products (UK):

• January–September: £0.52 per cubic foot per month
• October–December (peak season): £1.63 per cubic foot per month

Critical insight: These are monthly charges. A product occupying 0.5 cubic feet stored for six months costs 6 × the monthly fee. Example: 0.5 cu ft × £0.87/month × 6 months = £2.61 in storage fees alone. Before fulfilment or long-term storage charges apply.

Slow turnover directly multiplies costs. A product with average selling velocity must be evaluated against storage costs to determine true unit economics.

Long-Term Storage Fees

Inventory stored for 365 consecutive days or more incurs long-term storage fees. This is one of the most punitive charges in the FBA model.

Long-term storage fee: £6.90 per cubic foot.

This fee is charged every six months. A product occupying 0.5 cubic feet stored 12+ months incurs £6.90 × 0.5 = £3.45 every six months. Significantly more than standard monthly storage.

Example scenario: A product that sells slowly and accumulates inventory over time quickly becomes uneconomical:

• Product cost: £5
• Accumulated in FBA for 12 months: 200 units
• Total cubic footage: 200 × 0.05 cu ft per unit = 10 cu ft
• Long-term storage fee (6-month charge): 10 × £6.90 = £69 on top of monthly storage

Removing slow-moving inventory before the 365-day threshold is one of the most effective ways to protect margins. Sellers should regularly audit their Inventory Performance Index (IPI) score and remove or liquidate products approaching this threshold.

Optional Service Fees

Amazon offers several optional services that add cost:

• Labelling (FNSKU or barcode application): £0.50 per item for Amazon to apply barcode labels. For 1,000 units, this adds £500.
• Product preparation (bagging, wrapping, or opening packaging): Variable cost, typically £0.15–£0.50 per unit depending on complexity.
• Returns processing: Charged when customers return items for refund processing.
• Removal and disposal: Approximately £0.50 per unit to remove excess inventory or prepare for disposal.

Many sellers prepare inventory themselves to avoid these fees, particularly labelling costs. However, this requires logistics space and labour. The trade-off between Amazon prep and in-house prep should be evaluated case by case.

2026 FBA Fee Changes: What’s New

2026 Fee Reductions

Amazon made one of its largest-ever fee reductions in 2026, lowering FBA fulfilment fees by an average of £0.26 per unit in the UK. Low-Price FBA rates (formerly Small and Light, discontinued 2023) have been extended to products priced at or below £20 (up from £10), saving an average of £0.40 per unit for newly eligible products. Monthly storage fees saw a modest increase averaging £0.02 per unit. Referral fee reductions in specific categories: Clothing and Accessories down to 5% for items up to £15 and 10% for £15–£20; Home Products down to 8% for items up to £20; Pet Clothing and Food down to 5% for items up to £10; Grocery down to 5% for items up to £10. All effective from early 2026.

Amazon implemented several significant changes to the FBA fee structure in 2026. These changes reduce margins for most sellers:

FBA Prep Services Discontinued (January 2026)

Amazon discontinued FBA prep services, which previously allowed sellers to send unprepped inventory and have Amazon apply labels and prepare packages. Sellers must now prepare all inventory themselves. Adding labour costs, packaging materials, and logistics complexity.

Fulfilment Fee Increase (~£0.06–£0.08 per unit)

Average FBA fulfilment fees increased by approximately £0.06–£0.08 per unit across most categories, effective January 2026. For a high-velocity product selling 1,000 units monthly, this adds £60–£80 in monthly costs.

Fuel and Logistics Surcharge (April 2026)

A 3.5% fuel and logistics surcharge was added in April 2026. This equates to approximately £0.15–£0.25 per unit on average, further compressing margins. This surcharge is additional to base fulfilment fees.

Commingling Inventory Ending (March 2026)

Commingled inventory (shared stock with identical SKUs) is no longer permitted. Sellers must now use unique barcodes for each product, increasing inventory tracking complexity and preventing fungible units. This means counterfeit risk is reduced but inventory management becomes more granular.

Manufacturer Barcode Restrictions (March 2026)

Manufacturer barcodes (UPC/EAN) are now restricted to Brand Registry owners only. Sellers without brand registration must use Amazon-generated FNSKUs, eliminating opportunities to use standard retail barcodes. This increases reliance on Amazon’s labelling system.

Reimbursement Claims Window Shortened

The window to submit claims for lost or damaged inventory was reduced from 18 months to 60 days. This significantly impacts sellers’ ability to claim reimbursement, reducing protection for inventory in transit or damaged in fulfilment centres.

Reimbursement Basis Changed

Reimbursements for lost/damaged inventory are now calculated based on manufacturing cost rather than retail price, further reducing seller protection in the event of inventory loss.

How to Calculate Your True FBA Cost Per Unit

Total cost per unit includes multiple components. Here’s a worked example:

Scenario: A £20 product sold via FBA in the UK

• Product cost: £5.00
• Amazon referral fee (15% standard category): £3.00
• FBA fulfilment fee (Small Standard): £3.58
• Monthly storage allocation (assuming 90-day sell-through): £0.87/cu ft ÷ 3 months = £0.29 (per unit, 0.05 cu ft)
• Amazon advertising cost (typical 30% ACoS): £6.00 (30% of £20 sale)
• Payment processing (2.95% + £0.30): £0.89

Total cost: £5.00 + £3.00 + £3.58 + £0.29 + £6.00 + £0.89 = £18.76

Net profit per unit: £20.00 – £18.76 = £1.24 (6.2% margin)

This calculation reveals that a seemingly profitable £20 sale leaves only £1.24 in gross profit after all fees. Add tax, packaging materials, and customer service costs, and the product barely breaks even.

Use Amazon’s FBA fee calculator to run real numbers for your specific products. Update calculations monthly to account for fee increases and seasonal storage cost changes.

FBA Fee Comparison by Size Tier

Note: Fees current as of April 2026. Check Amazon Seller Central for the most recent pricing.

Strategies to Reduce FBA Fees

Right-Size Your Packaging

Package dimensions determine size tier. Moving from Large Standard to Small Standard can save £4–£5 per unit. Audit packaging and reduce dimensions where possible without compromising product protection. Even 1cm in each dimension can shift you into a lower tier.

Remove Slow-Moving Inventory Before 365 Days

Set a calendar reminder 11 months after sending inventory to Amazon. Products approaching the 365-day long-term storage threshold should be removed, liquidated, or heavily discounted before fees triple. Track velocity in Seller Central and use the IPI score as an early warning system.

Optimise Inbound Shipping to Amazon

Ship inventory in case-packed units (full cases) rather than mixed pallets. Case-packing reduces unloading and processing time at Amazon facilities, potentially lowering inbound fees. Plan shipments to match Amazon’s receiving capacity windows to avoid delays and additional handling charges.

Monitor Your Inventory Performance Index (IPI)

Your IPI score determines your quarterly storage limits. Sellers with IPI scores above 450 receive higher limits and lower penalties. Keep IPI strong by maintaining sell-through rates above 85%, removing stranded inventory, and minimising returns. Even a 50-point improvement in IPI can unlock storage capacity and reduce fees.

Calculate True Unit Economics Across Channels

Not every product should be sold via FBA. For low-velocity products (fewer than 5 sales per month), self-fulfillment or hybrid FBA/FBM approaches may be more cost-effective. Evaluate each product’s FBA versus FBM economics quarterly.

Negotiate Supplier Costs

With FBA fees rising, product cost becomes even more critical to margins. Re-negotiate supplier pricing, explore alternative manufacturers, or adjust product specifications to reduce cost by even 5–10%. Every pound saved on COGS directly offsets fee increases.

FBA Fees vs. Alternatives

Understanding FBA fees in context is important. Consider:

• FBM (Fulfilled by Merchant): Requires in-house logistics but eliminates fulfilment fees. However, FBM products lose Buy Box eligibility unless you offer Prime shipping via third-party logistics. Learn about Seller Fulfilled Prime requirements.
• Multi-channel fulfilment: Some sellers use FBA for Amazon and FBM for other channels (Shopify, eBay) to spread fixed costs across higher volume.
• Regional strategy: If fees in one marketplace (e.g., US) are significantly higher, consider focusing on lower-cost regions (e.g., EU markets) to maintain margins.

For details on the Buy Box and margin optimisation, read Amazon Buy Box Requirements.

Fee Differences: UK vs. US Marketplace

FBA fees are not standardised globally:

• Fulfilment fees: UK fees quoted in GBP, US in USD. A Small Standard item costs £3.58 in the UK. US fees are comparable after currency conversion, but true costs differ once you factor in exchange rates and tax.
• Storage fees: UK charges £0.87/cu ft (standard, Jan–Sept) vs. US rates, which differ by region and season.
• Long-term storage: £6.90/cu ft in UK; US rates are equivalent but in dollars.
• Optional services: Labelling and prep costs vary by market.
• Tax implications: VAT is embedded in UK pricing; US prices exclude sales tax, complicating margin calculations.

Always calculate margins separately for each marketplace. A product profitable in the US may be marginal in the UK due to fee differences and exchange rate fluctuations.

How to Monitor and Optimise Fees

• Monthly Seller Central review: Export your FBA report monthly and analyse fee trends. Are your storage fees climbing? Is long-term storage appearing?
• Set inventory velocity targets: Aim for 90-day or faster sell-through to minimise storage costs. Products with slower velocity should be re-evaluated for channel placement.
• Use Amazon’s fee calculator: Before launching new products, model fees for different price points and size tiers to ensure profitability.
• Track the 365-day threshold: Create a spreadsheet of your inventory with send dates. Flag items approaching long-term storage and plan removal or clearance.
• Compare your ACoS to industry benchmarks: Average ACoS is 30% across Amazon. If your advertising costs exceed this consistently, your product’s economics may be unsustainable.

For more on cost control and profitability optimisation, see Complete Guide to Amazon Seller Fees.

Getting Expert Help with Fee Optimisation

FBA fee structures are complex, and 2026 changes have affected every seller. If you’re uncertain about your fee structure or how to optimise your inventory for profitability, expert guidance can identify thousands of pounds in savings.

The team at VendLab specialises in Amazon seller cost optimisation and margin improvement. Contact our Amazon consulting team to review your current fee structure and develop a pricing and inventory strategy aligned with your margin targets. Or reach out today to discuss your specific situation.

Key Takeaways

• FBA fees include fulf
  

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