eBay Speaks in Codes. Here's the Decoder Ring
MC011. VeRO. Above Standard. Cassini. If you've spent any time selling on eBay, you've hit terms that stopped you mid-listing, or mid-panic. This glossary covers the full eBay seller vocabulary: from account metrics and restriction codes to fee structures and search visibility signals. Whether you're setting up your first listing or troubleshooting a suppressed one, every term you need is here.
Customer Service & Disputes
What is NAD / INAD (Not as Described / Item Not as Described)?
A return reason where a buyer claims the item doesn't match the listing description.
Why it matters: INAD returns are the most damaging metric to your seller account. eBay protects sellers on INAD return requests tied to misclassified conditions through the end of 2025. You must accept INAD returns and cover return shipping, regardless of your return policy.
What is INR (Item Not Received)?
A buyer claim that an item never arrived or was not available for collection.
Why it matters: High INR rates trigger selling restrictions or suspension. As long as you use eBay Labels (or integrate with approved carriers) and upload tracking within your stated handling time, you are fully protected from INR defects if the carrier experiences delays. If the item eventually arrives after you refund the buyer, eBay will reimburse you for the cost of the item.
What is UPI (Unpaid Item)?
When a buyer wins an auction or commits to purchase but fails to pay.
Why it matters: Sellers can open an Unpaid Item case 2 days after purchase. After 4 days, the seller can close the case. Use Unpaid Item Assistant to automate the process.
What is BBL (Blocked Buyer List)?
A list of buyers you've blocked from purchasing your items, bidding, or messaging you.
Why it matters: Blocking problematic buyers protects your account from non-payers and difficult customers. In 2026, sellers can choose whether to allow blocked buyers to contact them.
What is SEK?
It's the Swedish Krona, the official currency of Sweden.
Why it matters: Seeing it means your eBay currency display has shifted — and that shift is costing you a hidden 3% conversion fee on every transaction.
eBay Advertising
What is ACoS (Advertising Cost of Sales)?
A metric measuring ad efficiency: (Ad Spend ÷ Ad Revenue) × 100.
Why it matters: ACoS shows the percentage of ad-attributed sales spent on ads. A low ACoS (under 25%) generally indicates efficient campaigns.
What is CPA (Cost Per Acquisition / Cost Per Action)?
The cost to acquire a new customer or conversion.
Why it matters: CPA helps evaluate marketing efficiency. On eBay, a sensible CPA target is 40–55% of the sale price.
What is CPC (Cost Per Click)?
The amount you pay each time someone clicks on your ad.
Why it matters: eBay Promoted Listings use a CPC model — you only pay for clicks. CPC is based on a second-price auction (quality, keyword relevance, your bid, and competitors' bids).
What is DSP (Demand-Side Platform)?
A software platform used to buy digital ad inventory programmatically.
Why it matters: While eBay uses DSPs for its own ad buying, most eBay sellers focus on Promoted Listings rather than external DSPs.
What is eAAT (Estimated Arrival Time)?
The date range shown to buyers at checkout, calculated from handling time + shipping time.
Why it matters: Accurate eAAT builds trust and reduces INR claims. eBay recommends a handling time of no more than 2 days. Your past delivery performance influences the estimate.
What is PPC (Pay Per Click)?
An advertising model where you pay only when someone clicks your ad.
Why it matters: eBay's Promoted Listings use a PPC/CPC model. You set bids and daily budgets, and eBay caps monthly spend at ~30.4 × your daily budget.
What is ROAS (Return on Ad Spend)?
Revenue generated per dollar spent on ads: Ad Revenue ÷ Ad Spend.
Why it matters: ROAS is the inverse of ACoS. A ROAS of 4x+ ($4 revenue per $1 spend) is generally considered good.
What is ROI (Return on Investment)?
A broader metric measuring the profitability of an investment: (Gain − Cost) ÷ Cost.
Why it matters: ROI considers all costs (COGS, fees, shipping, ads), not just ad spend — use it for overall business health.
Describing Products / Item Condition
What is COA (Certificate of Authenticity)?
Documentation that vouches for the genuineness of an item (autograph, artwork, collectible).
Why it matters: COAs increase buyer confidence and item value. Blank COAs cannot be sold as stand-alone items.
What is NIB (New in Box)?
A brand-new item in its original box — may or may not be sealed.
Why it matters: NIB is slightly less strict than BNIB — the box may have been opened but the item is unused.
What is BNIB (Brand New in Box)?
A brand-new, unused item in its original, unopened box.
Why it matters: BNIB is the highest standard for new items — unopened and unused.
What is OEM (Original Equipment Manufacturer)?
On eBay, OEM refers to a product made by the original manufacturer but sold without retail packaging, manuals, or marketing trimmings. eBay has a strict policy regarding OEM software — it can only be sold with the original computer hardware it came with. Selling OEM software alone is prohibited.
Why it matters: OEM products are authentic but cheaper because they lack retail packaging. Crucially, if you list OEM software without hardware, eBay will remove your listing and may suspend your account.
What is VA (Virtual Assistant)?
An off-site professional who remotely manages eBay store operations — listing creation, order processing, inventory management, customer service, and product research.
Why it matters: A VA frees you from time-consuming daily tasks so you can focus on scaling your business. With proper training, a VA can handle the repetitive work while you focus on strategy and sourcing.
What is DOA (Dead on Arrival)?
An item that arrived damaged or completely non-functional.
Why it matters: A brand-new item marked as "Brand New" carries an implied warranty that it will work. If a buyer receives a DOA item, they can open an INAD case, and eBay will almost certainly side with them. Always test electronics before shipping.
What is EUC (Excellent Used Condition)?
A pre-owned item showing almost zero signs of wear — looks nearly pristine.
Why it matters: EUC is the highest used condition grade. Colors are bright, no flaws, minimal signs of use.
What is VGC (Very Good Condition)?
A used item with minor signs of wear — slightly more wear than EUC.
Why it matters: VGC is a step below EUC — minor scuffs or faint marks are acceptable.
What is FC (Fine Condition)?
An item in excellent shape with minimal wear and tear.
Why it matters: FC is similar to EUC — a high-grade used condition. No obvious damage.
What is G / GUC (Good / Good Used Condition)?
A used item with obvious signs of wear but still functional — minor scuffing, light scratches, softening of materials.
Why it matters: G is the minimum acceptable condition for many buyers. "Good" items show their age but work fine.
What is GU (Gently Used)?
An item with light signs of wear or use.
Why it matters: GU is essentially the same as "Good" condition — used but still in decent shape.
What is HTF (Hard to Find)?
An item that is scarce or difficult to locate.
Why it matters: HTF items can command premium prices, but the term is often overused. Genuine scarcity (not "I spent a week looking for it") drives collector value.
What is OOP (Out of Print)?
Publications (books, CDs, DVDs, video games) no longer being produced.
Why it matters: OOP items are inherently scarce and can appreciate significantly in value, especially in media collecting categories.
What is LTD (Limited)?
Short for "Limited Edition" — a product produced in a restricted quantity.
Why it matters: Limited editions create scarcity and urgency, often driving higher prices and faster sales.
What is MIB (Mint in Box)?
An item in perfect, unused condition still inside its original packaging, though the package may have been opened.
Why it matters: A step below MIMB, but still highly desirable for collectors. Knowing the distinction prevents mislabelling your listing and avoids buyer disputes over condition expectations.
What is MIMB (Mint in Mint Box)?
An item in flawless condition inside its original, sealed or intact box.
Why it matters: One of the highest condition grades in collectibles. Toy, game, and figure sellers use this to command top prices. Misusing it on a damaged box will trigger negative feedback fast.
What is MNB (Mint No Box)?
The item itself is in perfect condition but the original box is missing entirely.
Why it matters: Useful for sellers who acquired items without packaging. Clearly stating MNB manages buyer expectations upfront and protects you from "not as described" disputes.
What is MOC (Mint on Card)?
The item is mounted on its original display card (typical for action figures) in store-new condition.
Why it matters: MOC is the standard for carded collectibles. The card itself must be in mint condition — no shelf wear, no dents on the bubble.
What is MOMC (Mint on Mint Card)?
An item still attached to its original backing card, with both the item and card in perfect condition — common in action figures and trading cards.
Why it matters: Carded figures are a major collectibles niche. MOMC signals the card has no punched holes, bends, or yellowing — details that matter enormously to collectors and directly affect price.
What is MONMC (Mint on Near Mint Card)?
The item is perfect, but the backing card has minor, slight imperfections — a small crease, very light shelf wear.
Why it matters: Honest grading builds trust. Using MONMC instead of MOMC when the card isn't flawless signals credibility to experienced collectors and reduces return requests.
What is MWBT (Mint with Both Tags)?
An item, typically clothing or plush toys, that still has both the original hang tag and sewn-in label attached and intact.
Why it matters: In vintage fashion and Beanie Baby collecting especially, both tags being present can double or triple an item's value. Missing even one drops it to a lower condition tier.
What is MWMT (Mint with Mint Tags)?
The item is perfect and its tags are also in flawless condition — no bends, fading, or writing.
Why it matters: The highest tag-related grade. Beanie Baby and plush toy sellers use this extensively. A bent tag alone can move an item from MWMT to a lower grade, so photograph tags closely.
What is NBW (Never Been Worn)?
A clothing or accessory item that has never been put on, regardless of whether tags are present.
Why it matters: Distinct from NWT — an item can be NBW without tags if tags were removed but the item was never actually worn. Useful for vintage fashion sellers where original tags may no longer exist.
What is NC (No Cover)?
An item, typically a pen, marker, or similar product, missing its original cap or lid.
Why it matters: A small detail that matters in vintage stationery and collectible pen listings. Flagging it upfront avoids buyer disappointment and protects your feedback score.
What is NM (Near Mint)?
An item that is almost perfect with only the most minor, barely noticeable signs of handling or age.
Why it matters: A standard grading term across comics, cards, and collectibles. NM is one step below Mint; buyers understand the distinction and bid accordingly. Overstating condition as Mint when it's NM is one of the most common triggers for eBay disputes.
What is NRFB (Never Removed from Box)?
The item has never been taken out of its original box since manufacture.
Why it matters: Higher than MIB in some collector communities because it implies zero handling. Doll and figure collectors in particular pay a significant premium for NRFB status, often verifiable by intact factory tape or seals.
What is NOS (New Old Stock)?
An item that was manufactured and stocked years or decades ago but was never sold or used, remaining in original condition.
Why it matters: Huge in vintage automotive parts, electronics, and toy categories. NOS items are rare by definition and command strong prices, but buyers will scrutinize claims carefully, so provenance and photos matter.
What is NR (No Reserve)?
A listing in which the seller has not set a reserve price for an auction.
Why it matters: A reserve price is a minimum set by the seller for the auction to result in a sale — if it isn't met, the item doesn't sell. No reserve means people can bid as much or as little as they wish, which is why bargain-hunters watch for this acronym closely.
What is NWT (New with Tags)?
A brand new item with its original retail tags still attached.
Why it matters: The standard condition label for new clothing, accessories, and soft goods. Buyers searching for NWT expect tags to be undamaged and original, not reprinted or reattached after the fact.
What is NWOT (New without Tags)?
An item that is new and unused, but the original tags have been removed.
Why it matters: Common in gift items or clothing where tags were clipped before the item was listed. A lower price point than NWT is usually expected. Being upfront about NWOT prevents "not as described" cases.
What is NWOB (New without Box)?
An item that is new and unused, but the original box or packaging is absent.
Why it matters: Applies across electronics, shoes, and accessories. Buyers searching for NWOB are happy to trade packaging for a lower price — stating it clearly attracts the right buyers and avoids the wrong expectations.
What is OOAK (One of a Kind)?
A unique item — the only one in existence.
Why it matters: OOAK items are highly desirable for collectors and can command premium prices. The term is especially common in handmade crafts, art, and custom collectibles.
What is S/O (Sold Out)?
An item or product line no longer available through original retail channels.
Why it matters: A selling point, not just a status. S/O items on eBay often attract buyers who couldn't get them at retail — it signals scarcity and can justify a higher price point, especially in sneakers, limited editions, and toys.
What is SIG (Signature)?
An item bearing the authentic autograph or signature of a notable person — athlete, artist, celebrity, or otherwise.
Why it matters: Signed items are a high-value eBay niche with serious buyers and serious scrutiny. Listings claiming SIG without authentication documentation (COA) are a fraud risk and a VeRO concern. Always pair SIG with verifiable proof.
Product Identifiers
What is EAN (European Article Number)?
A 13-digit product identifier standard used primarily in Europe (GTIN-13 compliant).
Why it matters: Many eBay categories require product identifiers. Using valid EANs improves catalog matching and search visibility.
What is GTIN (Global Trade Item Number)?
An umbrella term for product identifiers including UPC, EAN, JAN, and ISBN.
Why it matters: eBay requires GTINs in many categories. Missing or invalid GTINs can prevent listing or reduce search ranking.
What is ISBN (International Standard Book Number)?
A unique identifier for books, either 10-digit or 13-digit format.
Why it matters: Required for book listings on eBay. Valid ISBNs link to eBay's catalog, improving discoverability.
What is MPN (Manufacturer Part Number)?
The unique number assigned by a manufacturer to a specific product part.
Why it matters: Required in many categories (especially electronics and auto parts). MPN + Brand helps eBay identify the exact product.
What is PN (Part Number)?
Another term for Manufacturer Part Number (MPN) — used interchangeably.
Why it matters: Same as MPN — essential for product identification in parts and accessories categories.
What is SKU (Stock Keeping Unit)?
A unique code used internally to track specific products or variants.
Why it matters: SKUs are your internal inventory backbone. eBay doesn't require them, but they're essential for your own tracking and multi-channel inventory management.
What is UPC (Universal Product Code)?
A 12-digit barcode standard used primarily in North America (GTIN-12 compliant).
Why it matters: Required for many eBay categories. Valid UPCs improve catalog matching and search ranking.
eBay Listings, Fulfillment & Operations
What is BIN (Buy It Now)?
A fixed-price option on auction listings, allowing buyers to purchase immediately at a set price.
Why it matters: BIN encourages quick sales — if a buyer meets the BIN price before the first bid, the item sells instantly. Many sellers report ~40% of items sell via BIN.
What is eBay Cassini?
eBay's internal search engine algorithm that determines how items are ranked.
Why it matters: Cassini tracks what listings buyers click, bid on, and how long they view. Sales history is a key ranking factor — established sellers rank higher. Active sellers who create new listings regularly improve their ranking.
What is OA (Online Arbitrage)?
Buying products from online retailers at a discount and reselling them on eBay for a profit.
Why it matters: Low barrier to entry, but requires speed and market research. Unlike Amazon, eBay does not restrict OA as severely, but authenticity and sourcing documentation remain critical.
What is RA (Retail Arbitrage)?
Buying products from physical retail stores (like Walmart or Costco) and reselling them on eBay.
Why it matters: Physical RA requires in-store scouting but can yield higher margins. eBay generally allows RA, but you need proper sourcing documentation to protect against authenticity claims.
What is DSR (Detailed Seller Rating)?
A 1-to-5 star rating buyers leave in four areas: item as described, communication, shipping time, and shipping and handling charges. Ratings are anonymous and averaged over 12 months.
Why it matters: DSRs directly affect your search ranking and buyer trust. Low DSRs can push your listings down in search results. To protect your DSR, accurately describe items, respond to messages promptly, and ship within your stated handling time.
What is FB (Feedback)?
eBay's equivalent of product reviews — the overall positive, neutral, or negative rating buyers leave after a transaction.
Why it matters: Your Feedback Score is the first thing buyers check. A high positive percentage builds trust and increases conversion. Negative feedback damages your reputation and can impact search visibility.
What is FVF (Final Value Fee)?
The fee eBay charges when an item sells — calculated as a percentage of the total sale amount (including item price, shipping, and taxes) plus a fixed portion.
Why it matters: FVF is your largest cost on eBay. The exact percentage varies by category. Important: in 2026, eBay removed the 10% FVF discount for Top Rated Plus listings. Factor FVF into your pricing from day one.
What is GTC (Good 'Til Cancelled)?
The only listing duration for fixed-price listings on eBay. The listing stays active until you cancel it or inventory runs out, and it automatically renews every 30 days.
Why it matters: GTC listings retain their item ID, URL, SEO benefits, watchers, and sales history when they renew. This builds long-term listing strength. Each renewal incurs a listing fee, so factor that into your monthly costs.
What is HTML (HyperText Markup Language)?
The long-form version of this acronym doesn't necessarily help you understand what it means or does if you're not familiar with coding — but it does appear on an eBay listing.
Why it matters: This section allows a seller to add more information to their listings, using either plain text or HTML, a coded template, to create a stylish piece of content.
What is NARU (Not a Registered User)?
eBay's status for a suspended or canceled account — applies to both buyers and sellers.
Why it matters: A NARU buyer's bids are canceled and you cannot complete transactions with them. The most common cause is an expired credit card or unpaid fees.
What is P&P (Postage & Packaging)?
The shipping cost charged to buyers, covering postage and packaging materials.
Why it matters: Unreasonable P&P costs discourage buyers. eBay enforces maximum P&P costs in certain categories.
What is BO (Best Offer)?
A feature allowing buyers to make a lower-priced offer on a fixed-price item.
Why it matters: BO increases conversion by letting price-sensitive buyers negotiate. Tiered discounts require at least 5% off for items under $200, 3% for $200–$1,000, and 2% for over $1,000.
What is IPR (Intellectual Property Rights)?
Legal rights protecting creations of the mind — trademarks, copyrights, patents.
Why it matters: Sellers are responsible for ensuring their items do not infringe on IPR. Violations trigger VeRO takedowns and potential suspension.
What is RMA (Return Merchandise Authorization)?
A unique number authorizing a return, provided by the seller before the buyer ships the item back.
Why it matters: You can turn on RMA in your Return Preferences to control the return process — communicate with buyers before providing a label. Missing RMA requirements can impact seller performance.
What is YTD (Year to Date)?
A metric covering the period from January 1 to the current date.
Why it matters: YTD is used for tracking cumulative sales, fees, and performance trends — critical for annual business planning.
What is FBA (Fulfillment by Amazon)?
Amazon's fulfillment service — Amazon stores, packs, and ships your products.
Why it matters: You can use your Amazon FBA inventory to fulfill eBay orders via Amazon Multi-Channel Fulfillment (MCF). eBay does not have its own fulfillment network.
What is 3PL (Third-Party Logistics)?
An external company that handles warehousing, picking, packing, and shipping.
Why it matters: 3PLs let you scale without building your own warehouse. Many 3PLs integrate directly with eBay for automated order processing.
eBay Platform Policies
What is OP (Original Post)?
The first post in a forum thread or discussion.
Why it matters: Used in eBay community forums when referring back to the original question or context. Not a seller metric — just forum etiquette.
What is TDR (Transaction Defect Rate)?
eBay's most critical measure of seller reliability, also known as Order Defect Rate (ODR). It tracks issues like late shipments, unresolved buyer complaints, and canceled transactions due to stock problems.
Why it matters: Exceeding the 2% TDR threshold can move your account into Below Standard status, resulting in higher fees, restricted selling privileges, and reduced search visibility.
What is VeRO (Verified Rights Owner)?
eBay's program allowing intellectual property rights owners to report counterfeit or infringing listings.
Why it matters: VeRO rights owners can submit a Notice of Claimed Infringement (NOCI) to have infringing listings removed. Sellers who receive VeRO takedowns risk account suspension.
What is TR / TRS (Top Rated Seller)?
The highest seller status on eBay, awarded to sellers who consistently provide excellent customer service.
Why it matters: TRS listings appear higher in search results. Top Rated Plus listings (with 1-day handling and 30-day free returns) get a 10% discount on final value fees and a Top Rated Plus seal. Requirements include ≥95% valid tracking rate, ≥95% on-time delivery rate, ≤1% dispute rate, and ≤1% return rate.
What is MC011 / MC999?
eBay restriction codes for account issues:
- MC011: Account verification — eBay needs to verify your identity or business activity.
- MC999: Catch-all code for policy violations or security issues.
Why it matters: These codes trigger account restrictions that prevent you from listing new items. The code tells you exactly what caused the issue, helping you fix it faster.