Amazon FBA fulfilment fees are what you pay per unit for Amazon to pick, pack, and ship each order from their UK warehouses. They are one of the largest costs in an FBA business and the single biggest reason product dimension and weight matter so much in sourcing decisions.
How FBA fulfilment fees work
Every product sent to Amazon FBA is assigned to a size tier based on its packaged dimensions and weight. Amazon measures and weighs items in their packaged state — as they will be shipped to the customer — and the tier determines the fee charged on every unit sold.
Amazon uses the greater of actual weight and dimensional weight (volume-based weight calculation) to determine fees on larger products.
UK FBA size tiers and fees (2026)
| Size tier | Max dimensions | Max weight | Fee |
|---|---|---|---|
| Small envelope | 33 × 23 × 2.5 cm | 100g | £1.98 |
| Standard envelope | 33 × 23 × 2.5 cm | 250g | £2.42 |
| Small parcel | 45 × 34 × 26 cm | 400g | £2.76 |
| Standard parcel | 61 × 46 × 46 cm | 12kg | £3.88 |
| Large parcel | 120 × 60 × 60 cm | 30kg | £5.31 |
| Extra large | Over large parcel | Any | £9.15+ |
These are standard-period rates (January–September). A product that sits precisely on the boundary of two tiers will always be classified in the higher (more expensive) tier.
What the FBA fulfilment fee does not include
The fulfilment fee covers pick, pack, and delivery only. It is separate from:
- Referral fee — Amazon's sales commission (charged on every sale, regardless of fulfilment method)
- Storage fee — monthly charge per cubic metre of warehouse space used
- Returns processing fee — applicable in some categories (mainly apparel)
- Labelling fee — optional service if you want Amazon to apply FNSKU labels
Your total per-sale Amazon cost is the referral fee plus the FBA fulfilment fee, not the fulfilment fee alone.
The cost impact of size tiers
The gap between tiers is significant and compounds at volume:
| Scenario | Fee | Difference at 200 units/month |
|---|---|---|
| Small parcel | £2.76 | — |
| Standard parcel | £3.88 | +£224/month (+£2,688/year) |
| Large parcel | £5.31 | +£510/month (+£6,120/year) |
A product that can be packaged to stay in the small parcel tier rather than standard parcel saves over £2,600/year at modest volumes. This is why packaging optimisation is worth investing time in during product development.
How to calculate your total Amazon cost per unit
Total Amazon cost = referral fee + FBA fulfilment fee
Example: Selling a home goods item at £26.00 (Home & Kitchen category)
- Referral fee (15%): £3.90
- FBA fulfilment fee (standard parcel): £3.88
- Total Amazon cost: £7.78 per unit
Remaining gross after Amazon fees: £18.22. If your landed cost is £7.00 and PPC is £1.50, net profit is £9.72 — a 37% margin.
Q4 storage fee impact on fulfilment economics
FBA fulfilment fees themselves do not change in Q4, but storage fees increase significantly from October to December. If you carry high inventory levels during Q4 that do not sell through as fast as expected, the elevated storage fees will erode margin on top of your regular fulfilment costs.
Best practice: send enough stock to last through Q4 demand without excess, arrive mid-September so you capture the full peak window, and create removal orders for any unsold seasonal stock before the new year.
Tips for staying in a lower fee tier
- Ask your supplier to optimise product packaging for dimension and weight
- Weigh and measure a sample unit in final packaging before calculating fees
- If a product is borderline on a tier boundary, test with a small order first
- Consider whether minimal retail packaging (poly-bag instead of box) changes your tier
Use an FBA fee calculator to model exact fees for your specific product dimensions and selling price before placing any order.