# Sourcing for Amazon FBA (CBM & Shipping Limits)
You find a brilliant product: a large, plastic outdoor dog house. It only costs $15 to manufacture in Ningbo. You can easily sell it for $90 on Amazon. The margin looks unbelievable.
You ship 500 units directly to an Amazon FBA warehouse. A month later, you look at your Amazon Seller Central dashboard. Amazon has charged you $4,000 in monthly storage fees and "Oversize" fulfillment fees. Even though you sold 100 units, your profit is negative. You realize you forgot to calculate the CBM (Cubic Meters) and the brutal reality of Amazon's dimensional weight penalties.
> **💡 Withyou Trip Expert Verdict:**
> "The absolute deadliest mistake in Amazon FBA sourcing is **Ignoring the Dimensional Weight (DIM Weight) and Oversize Tiers**. Amazon does not charge fulfillment fees based solely on how heavy an item is; they charge based on how much physical space it takes up on their warehouse shelf. If your product box is even 1/4 of an inch over the 'Standard Size' limit, your fulfillment fee instantly triples. You MUST ruthlessly engineer the product and its packaging to fit inside Amazon's 'Standard Size' dimensions."
## 1. The Amazon FBA Size Tier Matrix
| Amazon Size Tier | The Dimensions (Longest Side) | The Fulfillment Fee Impact | The Sourcing Verdict |
| :--- | :--- | :--- | :--- |
| **Small Standard** | Under 15 inches | ⭐⭐⭐⭐⭐ Extremely cheap. | The Holy Grail of FBA (e.g., phone cases). |
| **Large Standard** | Under 18 inches | ⭐⭐⭐⭐⭐ The sweet spot. | Perfect for most consumer goods. |
| **Small Oversize** | Over 18 inches | 🔴 **Instant Profit Killer.** | Fee jumps massively. Avoid unless margins are 80%+. |
| **Large Oversize** | Massive (Furniture) | 🔴 Requires specialized LTL freight. | Only for extremely high-ticket items ($300+). |
## 2. The Vacuum Packing and Folding Mandate
If you are shipping "air," you are losing money.
* **The Problem:** You are sourcing a plush dog bed. The bed is huge and fluffy. It measures 24 x 24 inches in the box. This instantly pushes it into Amazon's "Oversize" tier, destroying your profit.
* **The Execution:** You MUST force the Chinese factory to compress the product.
* **For Textiles/Foam:** Mandate **Industrial Vacuum Sealing**. The factory must suck all the air out of the dog bed and roll it into a tight cylinder that fits into a 16-inch box, dropping it back into the highly profitable "Large Standard" tier.
* **For Hard Goods:** Mandate **Knocked Down (KD) / Flat-Pack design**. If you sell a plastic storage bin, the factory must engineer it to nest inside each other, or fold completely flat.
## 3. The Amazon FBA Storage Limits (IPI Score)
You cannot use Amazon as your personal warehouse.
* **The Trap:** To save on ocean freight, you order 5,000 units (a full container) and tell the freight forwarder to deliver all of it directly to the Amazon FBA warehouse in Dallas.
* **The Reality:** Amazon will reject the shipment. Amazon heavily restricts how much inventory new sellers can send (Capacity Limits). Furthermore, if your product doesn't sell instantly, your Inventory Performance Index (IPI) score will plummet, and Amazon will charge you astronomical "Long-Term Storage Fees."
* **The Strategy (The 3PL Buffer):** You must never send a full container directly to Amazon. You send the container to a **Third-Party Logistics (3PL) Warehouse** in California. 3PLs charge pennies for storage compared to Amazon. You then drip-feed 500 units at a time from your 3PL to Amazon FBA via UPS ground shipping, ensuring you never trigger Amazon's massive storage penalties.
## ❓ Frequently Asked Questions (FAQ)
**Q: Should I let the Chinese factory stick the Amazon FNSKU barcode on the box, or do it myself?**
A: **Always make the factory do it.** Amazon requires a unique barcode (the FNSKU) on every single unit. If you send 1,000 blank boxes to Amazon, they will charge you $0.20 per unit to stick the label on for you (that's $200 wasted). You must download the FNSKU PDF from Seller Central and email it to the factory. However, do NOT let the factory just stick a paper label on the box (they peel off in transit). You must tell the factory: **"Print the FNSKU barcode directly onto the cardboard packaging design file."** It costs absolutely nothing, and it is 100% permanent.