What are prep services and how do they work for FBA?
Prep services sit between your supplier and Amazon’s fulfillment centers. Your manufacturer ships raw product to the prep center, and the prep center makes each unit FBA-compliant: applying FNSKU barcode labels, poly-bagging items that need suffocation warnings, bubble-wrapping fragile goods, bundling multi-packs, and building shipment-ready boxes that meet Amazon’s weight and dimension requirements.
Amazon also offers its own prep service (FBA Prep Service) at $0.50 to $1.00 per unit for labeling and $1.00 to $2.20 per unit for poly-bagging. Third-party prep centers typically charge $0.75 to $2.50 per unit for standard prep, with complex work (kitting, bundling, inspection) running $2.00 to $5.00 per unit. The advantage of third-party prep is quality control: they can inspect shipments from overseas suppliers, catch defects before units reach Amazon, and handle returns processing.
For FBA sellers doing $1M+ annually, prep services become essential when shipping volume exceeds what you can handle in-house. The break-even point is typically around 500 to 1,000 units per week: below that, self-prep in a garage or small warehouse is cost-effective. Above it, the labor savings of outsourcing to a prep center usually outweigh the per-unit fees.
Prep services cost comparison
| Prep task | Amazon FBA Prep | Third-party prep center | Self-prep (your labor) |
|---|---|---|---|
| FNSKU labeling | $0.55/unit | $0.20 to $0.50/unit | $0.03/label + your time |
| Poly-bagging | $1.00 to $2.20/unit | $0.50 to $1.50/unit | $0.10/bag + your time |
| Bubble wrap | $1.60/unit | $0.75 to $1.25/unit | $0.15/ft + your time |
| Bundling / kitting | Not available | $1.50 to $4.00/unit | Materials + your time |
| Inspection (QC) | Not available | $0.25 to $0.50/unit | Your time |
Example: prep cost impact on a $3.2M seller
A private label seller doing $3.2M across 35 ASINs ships roughly 4,200 units per week to FBA. Self-prepping at that volume requires 2 full-time warehouse employees ($18/hr x 40 hrs x 2 = $2,880/week in labor), plus $600/week in supplies (labels, poly-bags, boxes, tape), plus warehouse rent of roughly $1,200/week (2,000 sq ft at $2.50/sq ft/month). Total self-prep cost: ~$4,680/week or $1.11 per unit.
A third-party prep center charges $1.35 per unit all-in (labeling + poly-bag + inspection + box building). At 4,200 units/week that is $5,670/week. The prep center costs $990/week more than self-prep, but eliminates the need for warehouse space, employees, workers’ comp insurance, and the seller’s time managing the operation. For most sellers at this volume, the freed-up time to focus on sourcing and marketing generates more than $990/week in incremental revenue.
Common mistakes
- Not factoring prep costs into unit economics before sourcing. A product with 22% margin before prep can drop to 16% after adding $1.50/unit in prep fees. Run the full landed cost calculation including prep before committing to a new product.
- Using Amazon’s prep service without comparing costs. Amazon FBA Prep is convenient but often 30% to 50% more expensive than third-party centers for the same tasks. The exception is labeling-only, where Amazon’s $0.55/unit is competitive.
- Skipping quality inspection at the prep center. Having your prep center inspect 10% to 20% of inbound units catches supplier defects before they reach FBA. A 3% defect rate on 1,000 units at $25 ASP means $750 in potential returns plus negative reviews that damage your listing rank.