Amazon seller glossary: the terms you meet on Amazon and eBay UK

Seller Central and Seller Hub have their own vocabulary, and the same idea often has two or three names. This glossary explains the terms you meet when you sell on Amazon.com, Amazon.co.uk and eBay UK, and links to the official page where a marketplace defines a term itself.

Last checked: October 29, 2026

A-to-z Guarantee

Also called: A-to-z claim

Amazon's buyer protection for items bought from third-party sellers. When a buyer files a claim that is decided against you, it counts towards your order defect rate.

Account Health

Also called: seller performance, account health rating

The Seller Central page that shows whether you meet Amazon's performance targets and policies. Metrics such as order defect rate, late shipment rate and cancellation rate are tracked here, and low scores can lead to listing or account restrictions.

Amazon Brand Registry

Also called: Brand Registry, Brand Representative

A free Amazon programme for brand owners that helps protect and manage a brand's listings. To enrol you need a brand name or logo on your products or packaging and a pending or registered trademark from a government trademark office in a country with an Amazon store.

Official definition: Amazon: Brand Registry

API integration

Also called: Selling Partner API, SP-API, eBay API

A connection that lets software read and update your marketplace account directly, for example to sync stock, download orders or change prices. Amazon's version is the Selling Partner API; eBay offers its own developer APIs.

ASIN

Also called: Amazon Standard Identification Number

The 10-character code Amazon gives each product in its catalogue. Every seller of the same product sells against the same ASIN, which is why offers on one product page compete with each other.

Barcode (GTIN, EAN, UPC)

Also called: GTIN, EAN, UPC, product ID, manufacturer barcode

A Global Trade Item Number identifies a product across retailers. UPC is common in the US and EAN in the UK and Europe; marketplaces use it to match your listing to the right catalogue page, and an EAN-13 needs a GS1 company prefix.

Buy Box

Also called: Featured Offer, buybox

The Add to Basket and Buy Now area on an Amazon product page. When several sellers offer the same ASIN, Amazon picks one offer to show there, so winning it decides who gets most of the sales on that page.

Read more: how to win the buy box on amazon

Cancellation rate

Also called: pre-fulfilment cancel rate

The share of seller-fulfilled orders you cancel before dispatch, usually because the item was out of stock. Selling the same stock on several marketplaces without syncing it is a common cause.

Commingling

Also called: stickerless inventory, commingled inventory

Storing identical units from different sellers together in Amazon's warehouses and shipping whichever unit is closest. Amazon announced that it would end commingling for inventory shipped from 31 March 2026, with new barcode rules for brand owners and resellers.

Official definition: Amazon Seller Forums (UK): Commingling practices will end

Cross-border selling

Also called: international selling, export, eBay International Shipping

Selling to buyers in another country, either by listing on a foreign marketplace or by letting a marketplace programme handle export. On eBay UK, eBay International Shipping lets you send the item to a UK hub while eBay handles customs and international delivery.

Official definition: eBay UK Seller Centre: eBay International Shipping

Digital services fee

Also called: DST fee

A percentage Amazon adds to its Selling on Amazon and FBA fees to account for government digital services taxes. The rate depends on where you are established and which store the sale is in.

Official definition: Amazon Seller Forums (Europe): Update to digital services fee

Dimensional weight

Also called: volumetric weight, dim weight

A weight calculated from a parcel's length, width and height rather than its actual weight. Carriers and FBA size tiers use it, so a light but bulky product can cost more to ship than its scale weight suggests.

Easy & Free Returns

Also called: free returns

An eBay UK return option in which the seller offers free returns. From 8 June 2026 it is required on eligible parts and accessories listings, with at least a 30-day free return period for change-of-mind returns.

Official definition: eBay UK Seller Centre: Easy & Free Returns for Parts & Accessories

FBA (Fulfilment by Amazon)

Also called: Fulfillment by Amazon

A programme in which you send stock to Amazon's warehouses and Amazon stores, picks, packs and ships orders and handles customer service and returns. You pay fulfilment fees per unit and monthly storage fees for the space your stock takes up.

Official definition: Amazon: Fulfillment by Amazon

FBM (Fulfilled by Merchant)

Also called: merchant fulfilled, seller-fulfilled, MFN

Selling on Amazon while you store and dispatch orders yourself or through your own warehouse. Delivery promises, handling times and tracking are your responsibility, and they feed your performance metrics.

Final value fee

Also called: FVF, eBay selling fee

eBay's main fee when an item sells: a percentage of the total sale amount, which includes the item price, postage and applicable taxes, plus a per-order fee. The percentage depends on the category.

Official definition: eBay UK Help: Fees for business sellers · Read more: ebay fees uk

FNSKU

Also called: Amazon barcode, Amazon barcode sticker, X00 label

Amazon's own fulfilment barcode, which ties a unit in its warehouse to one seller. Resellers who are not Brand Representatives must label units with it from 31 March 2026, even when the product has a manufacturer barcode.

Official definition: Amazon Seller Forums (UK): Commingling practices will end

Fuel and logistics surcharge

Also called: fuel surcharge

A percentage Amazon adds to FBA fulfilment fees, not to your sale price, from 17 April 2026. Amazon describes it as temporary, and the rate differs between the US and Europe.

Official definition: Amazon Seller Forums (US): fuel and logistics surcharge

Fulfilment fee

Also called: FBA fee, pick and pack fee

The per-unit fee Amazon charges for picking, packing and shipping an FBA order. It depends on the product's size tier and weight and is separate from the referral fee.

Good 'Til Cancelled

Also called: GTC

An eBay listing duration in which the listing renews automatically each month until it sells out or you end it. Listing fees and optional upgrade fees apply again each month for these listings.

Official definition: eBay UK Help: Fees for business sellers

Handling time

Also called: dispatch time, Automated Handling Time

The number of business days between an order and its dispatch, which marketplaces use to calculate the delivery promise. On Amazon.com, seller-fulfilled SKUs must have accurate handling times from 29 June 2026.

Official definition: Amazon Seller Forums (US): New handling time requirements

Individual and Professional selling plans

Also called: selling plan, Pro account

Amazon's two account types. The Individual plan charges a fee per item sold, while the Professional plan has a monthly subscription plus selling fees.

Official definition: Amazon: Selling on Amazon fees

Item specifics

Also called: product attributes, aspects

Structured details on an eBay listing such as brand, size, colour or part number. Buyers filter search results with them, so missing item specifics make a listing harder to find.

Late shipment rate

Also called: LSR, late dispatch rate

The share of seller-fulfilled orders confirmed as dispatched after the expected date. Amazon and eBay both track it as a performance metric.

Lightning Deal and Best Deal

Also called: deals, promotions, Prime Exclusive Discount

Time-limited Amazon promotions that appear on the deals pages. They carry an upfront fee per promotion plus a variable fee on promotional sales, with a cap, and the amounts differ by store and event.

Listing

Also called: offer, product detail page

Your offer for a product on a marketplace: title, images, description, price, stock and delivery terms. On Amazon several sellers' offers can sit on one shared product page; on eBay each seller usually has a separate listing.

Low-Price FBA

Also called: low-price FBA rates

Reduced FBA fulfilment rates for inexpensive products. In Amazon's European stores the reduced rates were extended in January 2026 to most categories for products priced at or below £20.

Official definition: About Amazon EU: 2026 referral and FBA fee update

Multi-Channel Fulfilment (MCF)

Also called: Multi-Channel Fulfillment, Amazon MCF

An Amazon service that ships orders from other sales channels, such as your own website or another marketplace, out of your FBA stock. It has its own fees, separate from FBA.

Multichannel selling

Also called: multichannel ecommerce, selling on multiple marketplaces

Selling the same products on more than one marketplace or shop at once. The main operational risk is stock: unless quantities are synced, an item can sell twice and one order has to be cancelled.

Order defect rate

Also called: ODR

Amazon's headline customer-service metric: the share of orders with negative feedback, an A-to-z Guarantee claim or a chargeback. It is shown on the Account Health page.

Payout

Also called: disbursement, settlement, payment cycle

The transfer of your sales proceeds, minus marketplace fees, to your bank account. Amazon calls it a disbursement and eBay a payout; both show the fees deducted on a settlement or transaction report.

Peak fulfilment fee

Also called: holiday peak fee, festive peak fulfilment fee

A temporary addition to FBA fulfilment fees during the busy season. For 2026 Amazon applies it from 15 October 2026 to 14 January 2027 in the US and, for selected orders, in the UK and Germany.

Official definition: Amazon Seller Forums (UK): Peak season 2026

Per-order fee

Also called: fixed fee per order

The fixed part of eBay's final value fee, charged once per order on top of the percentage. On eBay UK it depends on whether the order total is above or below £10.

Official definition: eBay UK Help: Fees for business sellers

Prepaid return label

Also called: APRL, Amazon Prepaid Return Label

A return label Amazon generates for the buyer so they can send a seller-fulfilled item back without contacting you. From 8 February 2026, US sellers must use the programme for returns regardless of item value, with some exceptions.

Official definition: Amazon Seller Forums (US): Prepaid return labels for high-value items

Private seller and business seller

Also called: private account, business account

eBay UK treats the two account types differently. UK-based private sellers pay no final value fee or regulatory operating fee when their items sell (vehicle listings excepted), while business sellers pay both.

Official definition: eBay UK Help: Fees for private sellers

Promoted Listings

Also called: eBay ads, Promoted Shops

eBay's advertising for sellers, which places your listings higher in search and on other eBay pages. Its cost is set as an ad rate or bid and is charged on top of your selling fees.

Referral fee

Also called: commission, Amazon selling fee

The fee Amazon takes on each item sold: a percentage of the total price that varies by category, or a per-item minimum, whichever is greater. It is charged whether you use FBA or fulfil orders yourself.

Official definition: Amazon: Selling on Amazon fees

Regulatory operating fee

Also called: ROF

A percentage fee eBay UK charges business sellers on the total amount of each sale, including postage and taxes, on top of the final value fee.

Official definition: eBay UK Help: Fees for business sellers

Repricing

Also called: repricer, automated pricing

Adjusting your prices in response to competitors' offers, usually with rules such as a floor price you will not go below. On Amazon it is mostly used to stay competitive for the Buy Box.

Read more: amazon repricer

Seller performance levels

Also called: Top Rated Seller, Above Standard, Below Standard

eBay rates sellers as Top Rated, Above Standard or Below Standard according to their selling performance. On eBay UK, a seller who is Below Standard on the 20th of a month pays additional percentage points on top of the final value fee for sales in the following month.

Official definition: eBay UK Help: Fees for business sellers

SKU

Also called: stock keeping unit, seller SKU, MSKU

Your own code for a product or variant, chosen by you rather than the marketplace. Using the same SKU on every channel is what lets you match one product across marketplaces and keep its stock in sync.

Read more: how to create sku numbers

Sponsored Products

Also called: Amazon PPC, Sponsored Brands, Amazon Ads

Amazon's cost-per-click ads that promote individual listings in search results and on product pages; you pay only when a shopper clicks. Sponsored Brands are a related format that promotes your brand with video, images or product collections.

Official definition: Amazon: Advertising

Storage fee

Also called: monthly inventory storage fee, long-term storage fee

A monthly FBA fee for the space your stock occupies in Amazon's warehouses, measured by volume. Rates are higher from October to December, and stock kept too long can attract further inventory fees.

Official definition: Amazon: Fulfillment by Amazon

Valid tracking rate

Also called: VTR

The share of seller-fulfilled shipments with a tracking number the carrier can scan. Amazon tracks it as a performance metric for seller-fulfilled orders.

Variation

Also called: parent-child listing, variation listing, variant

One product sold in several versions, such as sizes or colours, grouped under a single listing. Each version usually has its own SKU, price, stock and barcode.

VAT

Also called: value added tax

The UK's sales tax on goods and services. Marketplace fee pages in the UK usually quote fees excluding VAT, and in some cases the marketplace rather than the seller collects VAT on the sale.