Choosing a 3PL for Amazon FBA is one of the highest-stakes decisions an Amazon seller makes. The wrong partner means late shipments, prep errors that trigger Amazon penalties, and inventory stuck in limbo. The right partner becomes invisible — your products flow to FBA seamlessly while you focus on sourcing and selling.
At 3PLGuys, we've processed millions of units for Amazon sellers from our Paramount, CA facility. Same-day prep for orders before 2 PM PT, direct integration with Seller Central, and error rates under 1%. We've seen what works and what fails sellers.
This checklist covers everything to evaluate when selecting an Amazon 3PL partner.
The Core Question: Prep Center vs. Full 3PL
Before evaluating partners, clarify what you need:
| Service Type | What They Do | Best For |
|---|
| Prep Center Only | Receives, preps, and ships to FBA | Sellers who only use FBA |
| 3PL + FBA Prep | Full fulfillment + FBA prep | Multi-channel sellers (FBA + Shopify, etc.) |
| FBA + FBM Hybrid | FBA prep + direct-to-customer shipping | Sellers hedging against FBA limitations |
If you only sell on Amazon and only use FBA, a dedicated prep center might suffice. If you sell multi-channel or want FBM backup capability, you need a full 3PL with FBA prep services.
Checklist: FBA Prep Capabilities
Labeling Services
| Capability | Why It Matters | Question to Ask |
|---|
| FNSKU labeling | Required for commingled-off inventory | "Do you apply FNSKU labels or suffocation warnings?" |
| Suffocation warnings | Required for poly bags | "What's your turnaround for labeling?" |
| Made in [Country] labels | Required for certain products | "Can you handle country-of-origin labeling?" |
| Expiration date labels | Required for consumables | "Do you support lot code and expiration labeling?" |
Prep Services
| Service | Amazon Requirement | Verification |
|---|
| Poly bagging | Products must be in sealed bags | Ask to see their poly bag inventory and sealing equipment |
| Bubble wrap | Fragile items need protection | Confirm they stock appropriate sizes |
| Box prep | Overboxing for fragile or multi-unit | Ask about carton specifications |
| Bundle creation | Multi-packs need specific prep | Request examples of previous bundle work |
| Set creation | Items sold together | Confirm they can create and label sets |
Quality Control
| Check | Why It Matters |
|---|
| Unit inspection | Catch damage before it reaches FBA |
| Barcode scanning | Verify correct FNSKU on every unit |
| Packaging inspection | Ensure prep meets Amazon standards |
| Photo documentation | Evidence if disputes arise |
Key Question: "What's your defect rate for FBA shipments? How many shipments get rejected or flagged by Amazon?"
Checklist: Amazon Integration
Seller Central Integration
| Feature | Benefit | Question |
|---|
| Direct API connection | Automatic shipment creation | "Do you integrate directly with Seller Central or use manual uploads?" |
| Shipping plan automation | Reduces manual work | "Can you auto-generate shipping plans from my inventory?" |
| Tracking sync | Visibility into shipments | "How do I track shipment status to FBA?" |
Shipment Types Supported
| Shipment Type | When Used | Confirm Support |
|---|
| Small parcel (SPD) | Lower quantities, faster check-in | Standard — all prep centers handle this |
| LTL (Less Than Truckload) | Larger shipments, lower per-unit cost | Ask about pallet building capabilities |
| FTL (Full Truckload) | High volume, lowest cost | Ask about dock access and trailer loading |
Inventory Management
| Capability | Why It Matters |
|---|
| Real-time inventory visibility | Know what's in stock, what's prepped, what's shipped |
| Low stock alerts | Trigger replenishment before stockouts |
| Lot tracking | Required for expiration-dated products |
| Multi-location support | If using multiple FBA warehouses or distributed inventory |
Checklist: Location and Speed
Geographic Considerations
| Factor | Impact |
|---|
| Proximity to FBA warehouses | Faster check-in, lower shipping costs |
| Port proximity (for imports) | Reduced drayage costs |
| Your supplier locations | Minimizes inbound shipping |
West Coast facilities (California) benefit sellers importing from Asia. East Coast or Midwest locations suit domestic sourcing or sellers targeting Eastern FBA warehouses.
Speed Benchmarks
| Metric | Good | Excellent |
|---|
| Receiving turnaround | 24-48 hours | Same day |
| Prep turnaround | 48-72 hours | 24 hours |
| Ship-out after prep | 24 hours | Same day |
| Total dock-to-FBA | 3-5 days | 1-2 days |
Key Question: "What's your average time from receiving my inventory to shipping to FBA?"
Cutoff Times
| Cutoff | What It Means |
|---|
| Same-day receiving cutoff | Inventory received by X time starts processing that day |
| Same-day ship cutoff | Orders completed by X time ship that day |
A 2 PM PT cutoff is standard. Earlier cutoffs (10 AM) may indicate capacity constraints.
Checklist: Pricing Structure
Common Fee Types
| Fee Type | What It Covers | Watch For |
|---|
| Receiving | Unloading, counting, checking in | Per-unit vs. per-carton pricing |
| Storage | Warehouse space | Monthly vs. daily rates; cube vs. pallet |
| Prep (per unit) | Labeling, poly bagging, etc. | Bundled vs. itemized |
| Pick and pack | Pulling and packing for shipment | Per-unit vs. per-order |
| Shipping | Carrier costs to FBA | Markup percentage; carrier options |
| Minimum fees | Monthly minimums | Can kill margins for smaller sellers |
Pricing Models
| Model | Description | Best For |
|---|
| Per-unit | Fixed fee per unit processed | High-volume, consistent products |
| Per-service | Itemized fees for each prep step | Variable prep requirements |
| Tiered | Lower rates at higher volumes | Growing sellers |
| All-inclusive | One price covers everything | Predictability over optimization |
Hidden Cost Red Flags
- Long-term storage fees that kick in faster than Amazon's
- Project fees for any special handling
- Accessorial charges not disclosed upfront
- Minimum monthly charges that exceed your volume
- Receiving fees per carton when you ship many small cartons
Key Question: "Show me a sample invoice for 1,000 units of a standard product receiving, prep, and FBA shipment."
Checklist: Communication and Support
Responsiveness Standards
| Channel | Expected Response Time |
|---|
| Email | Same business day |
| Phone | Live answer or callback within hours |
| Chat | Real-time during business hours |
| Account manager | Dedicated contact for accounts over $X |
Reporting Capabilities
| Report | Frequency | Why It Matters |
|---|
| Inventory levels | Real-time | Prevents stockouts |
| Shipment tracking | Per shipment | Confirms FBA delivery |
| Prep status | Daily | Visibility into workflow |
| Cost reports | Monthly | Budget management |
| Error/issue log | As needed | Quality tracking |
Problem Resolution
| Scenario | Expected Handling |
|---|
| Amazon rejects shipment | Identify cause, reprocess, reship without added fees (if 3PL error) |
| Inventory discrepancy | Investigate and reconcile within 48 hours |
| Damaged product | Document, report, handle according to agreed policy |
| Rush shipment needed | Clear process and pricing for expedited handling |
Key Question: "What happens if Amazon rejects a shipment due to a prep error on your end?"
Checklist: Scalability
Capacity Questions
| Question | Why It Matters |
|---|
| "What's your current capacity utilization?" | Near-capacity = potential delays during your growth |
| "How much can you scale my account in 90 days?" | Tests their growth capability |
| "What happens during Q4 peak season?" | Ensures they won't deprioritize you |
| "Do you have overflow or backup facilities?" | Contingency for demand spikes |
Growth Accommodation
| Need | What to Confirm |
|---|
| SKU expansion | No per-SKU fees that penalize variety |
| Volume increases | Tiered pricing that rewards growth |
| New channels | Ability to add FBM, Shopify, etc. |
| New prep types | Flexibility for different product categories |
Checklist: Contract and Terms
Contract Elements to Review
| Element | What to Look For |
|---|
| Length | Monthly preferred; avoid long-term lock-in initially |
| Termination | 30-day notice standard; watch for penalties |
| Price changes | How much notice? Annual caps? |
| Liability | Coverage for damaged/lost inventory |
| Insurance | Their coverage limits; your responsibility |
| Data ownership | You own your inventory and order data |
Liability and Insurance
| Coverage | Standard Expectation |
|---|
| Lost inventory | Replacement at cost or wholesale value |
| Damaged inventory | Replacement at cost |
| Prep errors | Rework at no charge |
| Liability cap | Often limited to inventory value |
Key Question: "If you lose or damage my inventory, what's the claim process and compensation?"
Red Flags to Avoid
| Red Flag | Why It's Concerning |
|---|
| No Amazon-specific experience | FBA prep is specialized; general warehousing isn't enough |
| Can't provide error rate metrics | Either don't track or don't want to share |
| No references from Amazon sellers | Unproven with your use case |
| Long-term contract required upfront | Confidence issue; can't earn your business monthly |
| Pricing that seems too low | Will surface in hidden fees or poor service |
| No real-time inventory visibility | Operating with outdated systems |
| Slow communication during sales process | Won't improve after you sign |
Evaluation Process
Step 1: Initial Screening (5-10 candidates)
- Review websites and service lists
- Confirm FBA prep is a core service (not an afterthought)
- Check location alignment with your needs
- Request pricing information
Step 2: Deep Evaluation (3-5 candidates)
- Detailed pricing quotes for your specific products
- Reference calls with current Amazon seller clients
- Review of their technology and integrations
- Q&A on all checklist items above
Step 3: Final Selection (1-2 candidates)
- Facility tour (virtual or in-person)
- Trial shipment with a subset of inventory
- Contract negotiation
- Onboarding timeline and process
Trial Shipment Best Practices
| Practice | Rationale |
|---|
| Send representative SKUs | Include your most complex prep requirements |
| Track timing precisely | Measure against their stated turnaround |
| Verify FBA check-in | Confirm shipment accepted without issues |
| Note communication quality | Reflects ongoing experience |
| Calculate true costs | Compare quoted vs. actual |
Making the Final Decision
The best Amazon 3PL partner is rarely the cheapest. Evaluate total cost including:
- Direct fees
- Your time managing the relationship
- Error and rework costs
- Opportunity cost of slow turnaround
- Risk of stockouts from delays
A partner that costs 10% more but processes faster, makes fewer errors, and requires less oversight often delivers better ROI.
At 3PLGuys, we offer trial shipments and transparent pricing. Request a quote to see how we handle your specific FBA prep requirements.
