The Amazon Seller Glossary: Terms Every FBA Seller Should Know

Amazon has its own language, and the jargon can be a real barrier when you're starting out. This glossary covers the terms you'll actually run into selling on Amazon in 2026, explained in plain English. I've grouped them roughly by where they come up so it reads like something useful rather than a dictionary.

Identifiers and catalog

• ASIN — Amazon Standard Identification Number. Amazon's unique ID for a product listing. Every listing has one.
• SKU — Stock Keeping Unit. Your own internal code for a product. You assign it; Amazon maps it to an ASIN.
• GTIN — Global Trade Item Number. The umbrella term for a product's global barcode number. UPCs and EANs are types of GTIN. (If a listing goes down over a GTIN mismatch, here's how to fix a down listing with a GTIN/UPC issue.)
• UPC / EAN — the actual barcode numbers (12-digit UPC in North America, 13-digit EAN internationally). As of 2026 you must source these from GS1, not third-party resellers.
• FNSKU — Fulfillment Network Stock Keeping Unit. The Amazon-specific barcode you put on each physical unit you send to FBA, so Amazon tracks your inventory specifically.
• GTIN exemption — permission from Amazon to list without a UPC, available for some unbranded or private-label products in eligible categories. Here's how to apply for a product ID exemption.

Fulfillment

• FBA — Fulfillment by Amazon. You send inventory to Amazon's warehouses; they store, pick, pack, ship, and handle customer service for a fee. Products become Prime-eligible. (See our step-by-step guide to sending an FBA shipment.)
• FBM / MFN — Fulfilled by Merchant / Merchant Fulfilled Network. You store and ship orders yourself. (Getting this right depends on your FBM shipping template.)
• SFP — Seller Fulfilled Prime. You ship yourself but still earn the Prime badge by meeting Amazon's speed and performance requirements.
• Send to Amazon — the current Seller Central workflow for creating FBA shipments.
• Commingling — when Amazon pools identical units from multiple sellers (using manufacturer barcodes instead of FNSKU). Generally not recommended, because you can be blamed for another seller's defective stock.
• Removal / disposal order — instructing Amazon to send your FBA inventory back to you or dispose of it.

Advertising

• PPC — Pay Per Click. Amazon's advertising model where you pay when someone clicks your ad.
• Sponsored Products / Brands / Display — the three main self-serve ad types: in-search product ads, brand/banner ads, and retargeting/audience ads. (See our overview of the Sponsored campaign ad types.)
• DSP — Demand-Side Platform. Amazon's programmatic advertising for display and video, on and off Amazon. Higher minimums and complexity.
• ACoS — Advertising Cost of Sale. Ad spend divided by ad-attributed sales. Measures campaign efficiency.
• TACoS — Total Advertising Cost of Sale. Ad spend divided by total revenue (ad-driven plus organic). The strategic metric, because it shows whether ads are growing your organic business.
• ROAS — Return on Ad Spend. The inverse of ACoS expressed as a multiple (a 20% ACoS equals a 5x ROAS).
• NTB — New-to-Brand. Metrics showing how much of your advertised revenue comes from customers buying your brand for the first time.

Ranking and listings

• A9 / "A10" — Amazon's search ranking algorithm. A9 is the historical name; "A10" is the community term for its evolution toward conversion, engagement, and customer-satisfaction signals. (See how Amazon SEO works.)
• Buy Box — the "Add to Cart" box on a listing. When multiple sellers offer the same product, only one "wins" the Buy Box at a time. Winning it is critical to sales.
• A+ Content — enhanced listing content (rich images and modules) available to Brand Registered sellers.
• Rufus — Amazon's AI shopping assistant, which answers shopper questions and surfaces products by intent.
• BSR — Best Sellers Rank. A category ranking that roughly indicates how well a product is selling relative to others in its category.
• Backend keywords / search terms — hidden keyword fields in your listing that help Amazon index your product.

Brand, compliance, and account health

• Brand Registry — Amazon's program for brand owners (requires a registered trademark) that unlocks A+ Content, Stores, brand analytics, and protection tools. (See how to protect your brand with Brand Registry.)
• Account Health / AHR — Account Health Rating. Amazon's scoring of your policy compliance and performance. A low rating risks suspension.
• ODR — Order Defect Rate. The percentage of orders with a defect (negative feedback, A-to-z claim, chargeback). Staying under 1% matters.
• Plan of Action (POA) — the structured appeal document you submit to get a suspended listing or account reinstated. (See how to solve hard Amazon cases and appeals.)
• Section 3 — the part of Amazon's Business Solutions Agreement covering serious account-level enforcement (fraud, related accounts, deceptive activity). Section 3 suspensions are among the hardest to resolve.
• IP complaint — an intellectual property complaint (trademark, copyright, or patent) filed against your listing, which can lead to removal. (Related: what to do if your listing is hijacked.)

Business and finance

• 1P vs 3P — First Party (you sell wholesale to Amazon via Vendor Central; Amazon is the seller) vs Third Party (you sell directly to customers via Seller Central).
• Vendor Central / Seller Central — the two main platforms: Vendor Central (1P, invitation-only) and Seller Central (3P, open to sellers).
• Referral fee — Amazon's commission on each sale, commonly around 15% depending on category. (Fees change often — see the 2026 FBA fee changes.)
• MOQ — Minimum Order Quantity. The smallest order a supplier will accept (often negotiable).
• Landed cost — your total cost to get a unit to the warehouse: product + freight + duties.

Keep this page bookmarked. The fastest way to feel less lost on Amazon is to stop letting the acronyms slow you down — once the vocabulary clicks, most of the strategy advice out there becomes far easier to follow.