You got a duplicate-ASIN error 8573, someone pointed out that your ASIN is a duplicate, or a bulk upload through a tool created a product page you don't recognize. This article is for sellers in that situation. We cover how to tell which path caused the duplicate, what to check before you delete anything, how to decide whether creating a new ASIN is appropriate, what to inspect in your external tools, and the official procedures for resolving the duplication.
What counts as a "duplicate": how ASINs, product codes, and SKUs relate to the rules
Amazon supports only a single product detail page for a single product. If a product is already in the catalog, you list against the existing ASIN, and you create a new ASIN only for products that aren't in the catalog yet. Three identifiers are involved:
| Identifier | Who assigns/sets it | Role |
|---|---|---|
| ASIN (Amazon Standard Identification Number) | Amazon (assigned when a product is added to the catalog) | The number for the product detail page; shared by every seller of that product |
| Product code (GTIN; generally a JAN code in Japan) | The company that owns the product's brand (in Japan, set using a GS1 company prefix licensed from GS1 Japan) | Used to match against an existing ASIN |
| SKU | The seller | The number a seller uses to manage their own listing |
The Product Detail Page Rules prohibit creating duplicate pages, including for products already listed in other Amazon stores. "Seller Prohibited Activities and Actions" also has a section on "duplicate product detail pages," and that same page lists removal of listings, loss of listing privileges, and permanent suspension among the consequences for non-compliance. Both this rule and the ASIN Creation Policy (商品詳細ページ（ASIN）の新規作成に関するポリシー) are covered by the Account Health Rating.
This article is based on Help content and other materials as of September 2026. Policies and on-screen labels can change, so please also check the latest information.
Editing an existing page is the same underlying problem
A product detail page is shared with other sellers. Don't change or add to the product name, brand name, or manufacturer name on an existing ASIN; if something is wrong, gather supporting evidence and ask Amazon Technical Support (Amazonテクニカルサポート) to correct it. Listing a product with a different edition or compatibility on an existing page also counts as "inaccurate product information" (for warnings in general, see responding to inaccurate or inappropriate content warnings).
Three paths to a duplicate: identifying your case
Which screens and procedures apply depends on who created the duplicate and how. Find the case closest to yours.
| Path | Likely situation | How you notice | Main procedure |
|---|---|---|---|
| A. You created it | A new listing was created without first searching the catalog (even via a tool, Amazon sees it as a submission from your own account) | A Performance Notification, an Account Health (アカウント健全性) violation entry (error 8573 at registration is a sign that stopped the creation before it happened) | Follow the instructions in the notification, request a merge, or contact Technical Support |
| B. Another seller or the system | Another seller created a separate ASIN with the same barcode (a new duplicate). Note: if the catalog auto-merged two different products into one page by mistake, that isn't a new duplicate but a "mis-merge," handled with the split procedure described below | A change in SKU status, a sudden sales drop, a catalog notification | Request a merge or split, or use "Report Abuse or a Violation" (不正または違反を報告) |
| C. Tool or file settings | A tool was sending product information along with listing data, or manual edits and a tool were updating the same SKU at the same time | Errors in a processing report, an unfamiliar ASIN or SKU | Stop the submissions and isolate the cause, then review your operating procedures |
The first thing to check: document before you delete
"Delete Product and Listing" (商品と出品を削除) can't be undone, and it also affects the conditions for the merge procedure described later. Work through the following steps, in order, to check and record what's happening before you act.
STEP 1. Read what a Performance Notification is actually asking for
Open the menu (the three-line icon at the top left of the screen) > Performance > Performance Notifications (パフォーマンス通知), and write down the policy name, the affected ASIN, what response is requested, and the deadline if one is given. What matters isn't a general explanation but the specific instructions in the notification you received. Amazon staff have said on the Seller Forums that if a notification only describes how to dispute an incorrect determination, submitting a plan of action or similar document is unlikely to be accepted.
STEP 2. Check your Account Health and inventory status
Check the Product Policy Compliance (商品規約の遵守) tab under Account Health (アカウント健全性) for any violation notices, and if none appear, check Manage All Inventory (全在庫の管理) for any listings that have been suspended. If your account has been suspended, appeal through Reactivate Your Selling Account (出品用アカウントの再開) (the overall flow is covered in from account suspension to reinstatement). How to read your score is covered in checking your Account Health Rating.
Also check the ASIN linked to the affected SKU and its status. If you suspect path B, also look at the content and recent sales history of the original ASIN's page.
STEP 3. Save your screenshots and records
What to save before taking any action
- Screenshots of the Performance Notification and any violation entry (with dates visible)
- The product detail pages for both of the duplicate ASINs
- Your own SKU, product code, registration date, and the method used to register it
- The error screen from registration (showing the code and time)
- Inventory file processing reports and batch IDs, and your tool's submission logs
Registration errors and deciding whether a new ASIN is warranted
On the Add a Product (商品登録) page, options for listing against an existing product are shown first, and the blank form is described as being for use "when you can't register using the options above."
Error codes to check at registration (duplication, product code, creation limits)
| Error | What it generally means | Suggested direction |
|---|---|---|
| 8573 | An ASIN that exactly matches what you submitted may already be in the catalog | Search for the existing ASIN using the steps below |
| 8541 | The brand, product name, color, or similar attribute you submitted conflicts with the existing ASIN | If it's the same product, accept Amazon's information via "Correct Product Information" (商品情報を修正); if it's a different product, report the difference |
| 8542 | One product code is linked to two or more ASINs, and none of the other information you submitted matches any of them | Help doesn't describe a dedicated resolution for 8542. Explain the error and contact Technical Support |
| 8566 / 8567 | The registered product code and brand name don't match, among other causes (8566 can also appear when there's no sales history and the ASIN can't be created) | If the mismatch is the cause, confirm the GS1 registration and that the brand name matches exactly, then resubmit using a new blank template |
| 8572 | The product code you used doesn't match the product or brand | Creating a listing with an inaccurate code is prohibited. If your code is correct, contact Technical Support with supporting evidence |
| 8571 / 8575 | You've hit the limit on the number of ASINs you can create, or a temporary hold from creating too many in a short period | You can still list against existing ASINs even with error 8571. Error 8575 is generally described as clearing automatically after about a week |
If you get error 8573, check in this order:
- Under Catalog (カタログ) > Add a Product (商品登録), search by the product code as well as by keywords for brand name, model number, and product name
- If a matching ASIN turns up, list against it via "Sell this product" (この商品を出品する) or "Match this ASIN" (このASINと照合する)
- If nothing turns up, confirm whether it's genuinely a new product by checking the model number and set contents
- If you're confident it isn't already registered, report error 8573 and contact Technical Support
Table: when a separate ASIN is or isn't warranted
This is based on Help content and the product-registration rules. Also check the category-specific requirements that apply to you.
| Situation | General guidance |
|---|---|
| Only the packaging color, design, or material changes; the product inside is unchanged | No new ASIN is needed — list against the existing ASIN (if the product itself changes color, size, materials, or function, check the row below instead) |
| A significantly different new model of the product itself (Help's example: the included remote control changes from two buttons to four) | Create a new ASIN. Don't list the new version under the existing listing |
| Sold under a different trademark (brand) | Don't edit the existing ASIN; create a new one |
| You've added your own color option or logo to a manufacturer's JAN product | Get a new JAN code and note the difference in the product name (e.g., "with XXX logo") |
| Bulk products (white-box goods), multi-packs of the same product, or lucky bags | Register on a separate page with a separate product code from the regular retail or single-unit product. For bulk goods, note "bulk" or similar in the product name. For multi-packs, if an existing page's contents and quantity match exactly, confirm the match before listing on it; if the contents differ even slightly, register on a new page with a new product code |
| The same product already has a page in another country's Amazon store | Don't create a new page. Search for the existing ASIN and list against it if you find it; if you can't find it or aren't sure, consult Technical Support |
When you do create a new ASIN, the product code must be one you own or are authorized to use, and it's checked against the GS1 database (when listing against an existing product, use that product's own legitimate code to search for the existing ASIN). Amazon doesn't accept barcodes obtained from third parties, and listing false product identification information can lead to suspension or removal of your ASIN-creation or selling privileges. Except when created under an exemption, a product code can't be changed once the listing exists.
Checking your external tools and integrations
Under the Amazon Services Business Solutions Agreement, the Selling Partner API terms hold sellers solely responsible for actions taken using their account ID and credentials, including actions taken by a third party. Don't assume a tool malfunction reduces your responsibility — treat the tool as something to inspect while you track down the cause. If you're unsure how to interpret the agreement, check with a professional such as a lawyer.
Check 1. Take stock of everything connected to your account
Under Settings (設定) > User Permissions (ユーザー権限), review "Manage Employees" (従業員の管理) and, if you're a Professional seller, "Manage Service Provider Access" (サービスの管理) to see which employees and service providers have access. Also check which apps are connected, and consider disconnecting any integration you no longer use. Removing a service provider's access can't be undone, so read the note at the end of Check 4 before you disconnect anything.
Check 2. What is being sent, and how
The Selling Partner API distinguishes between submissions that include "both product information and offer information," "product information only," and "offer information only," and between updates that replace the whole listing and updates that touch only part of it. Confirm with your provider which type your tool uses.
If your tool has been sending product information to an existing ASIN, stop the submissions and check whether the page's product name, brand name, or other fields have been overwritten with your data. If an inaccurate entry remains, ask Amazon Technical Support to correct it, attaching something like the manufacturer's URL that shows the correct product code.
Questions to ask your tool provider
- Does listing against an existing ASIN also send product information?
- Is there a setting that automatically creates a new ASIN when it can't match an existing one?
- Are updates full replacements or partial updates?
- Where and for how long can you check the submission history and errors?
Check 3. Settle on a single way to send updates
Help for error 8541 recommends using only one of the listing feed, the Add a Product page, or the Selling Partner API to create listing information. Avoid a setup where manual edits and a tool alternate updating the same SKU.
Check 4. Keep processing reports and isolate the cause by pausing the tool
Upload status shows the date, time, batch ID, and result, and processing reports record validation results and errors for the values you submitted. Because the history you can view is limited, save copies on your own.
While the cause is still unclear, pause automatic submissions from any tool you suspect, and check whether the issue still occurs when you work only through the Seller Central screens. Help for "Selling Partner API" (出品API) directs technical issues with the API to Developer Support.
Don't stop at the ASIN that was flagged. List every SKU sent by the same tool over the same period, from your processing reports or Manage All Inventory (全在庫の管理), and search by product code, brand name, and model number to check for any overlap with existing ASINs. Handle anything you find using the same process.
Note that removing a service provider's access stops automated processing immediately. There's no way to undo the removal, and re-enabling it requires approving access again. Contracts outside Seller Central aren't cancelled by this action.
The official procedures for resolving a duplicate
The two official ways to resolve a duplicate are requesting a merge and contacting Technical Support. Deleting your SKU doesn't necessarily remove the ASIN from the catalog.
| Procedure | When to use it, and key conditions/notes |
|---|---|
| Merge | When the same product has ended up on separate pages. Both ASINs need active listings, and every attribute must match exactly. Brand-registered ASINs (except at the rights owner's request), different brands, and parent ASINs, among others, aren't eligible |
| Split (unmerge) | When different products were merged by mistake. The products must be substantially different, and there must be a merge history |
| Remap | An exceptional procedure to move a SKU to the correct ASIN. Ten or more requests to a non-matching ASIN within 30 days can restrict this for the following 30 days |
| Close Listing (出品を終了) | The listing status becomes inactive, and your sales history remains. You can relist later |
| Delete Product and Listing (商品と出品を削除) | Your SKU and its sales history and product information are permanently removed from your selling account, and this can't be undone (the ASIN may still remain in the catalog). If you sell it again, wait 24 hours before re-registering |
Requesting a merge or split
For a merge, use the "merge duplicate product detail pages" self-service tool (重複している商品詳細ページの統合セルフサービスツール) and submit the source and target ASINs, evidence that they're the same product, and your reason for the merge. Processing can take up to 24 hours, and after the merge the target ASIN becomes the surviving page (Amazon may decide which ASIN survives in some cases). If the merge tool can't complete it, contact Technical Support (see organizing what to tell Technical Support).
A merge requires that both ASINs have active listings, so removing your own listing too soon can mean the condition is no longer met. That said, if a Performance Notification instructs you to remove or fix a listing, follow that instruction first. One example of how to proceed under path A:
- Check exactly what the Performance Notification is asking you to do
- Identify the existing ASIN you should actually be listing against, and save both pages
- If you meet the conditions for a merge, submit it through the self-service tool; if you don't, or you're unsure, contact Technical Support with your records attached
- Once you've received guidance, handle the unneeded SKU with "Close Listing" or "Delete Product and Listing" (note the order relative to your merge request, since "Close Listing" also takes the listing out of active status)
If the opposite happened — products were merged by mistake — request that it be undone through the "split product detail pages" self-service tool (商品詳細ページの分割セルフサービスツール), attaching both ASINs, why they're different, and photos showing the differences.
Under path B, if you find a duplicate page created by another seller, use "Report Abuse or a Violation" (不正または違反を報告) to submit the ASIN, the other seller's store name, the product name, and a description of the violation. Amazon doesn't disclose the outcome of the investigation. For how to keep records, documenting and reporting suspected harassment may also be useful.
Deleting your SKU doesn't remove the violation entry
Amazon's official Account Health FAQ states explicitly that a status change such as closing or deleting a listing doesn't remove a violation. A violation is removed only when, for example, a dispute confirms the determination was wrong, corrective action is confirmed, or 180 days have passed since it was added. However, while an account is deactivated because of its Account Health Rating, violations remain even after 180 days.
When you're asked for an explanation or supporting documents
If a notification requests something like a plan of action, don't just say "the tool caused it." Describe which setting or step led to the duplicate and exactly what you changed (see also how to build a plan of action). Below is a sample outline for that kind of explanation — a hypothetical example, not a real case.
A bulk submission from our inventory-sync tool created a new ASIN for a product that should have been listed against an existing ASIN. We had no step to search before registering, and we hadn't confirmed how the tool behaved when it couldn't find a match.
We identified the affected SKU, stopped the automatic submissions, and contacted Technical Support about how to handle the duplicate ASIN.
Going forward, we will record our search results before every new registration, and any change to our submission settings will be confirmed by two staff members.
Things not to do
- Opening a new account to keep selling: Under the Seller Code of Conduct, you're generally allowed only one account per region you sell in, except where you have a legitimate business reason and every account is in good standing. Creating an account to get around a suspension violates the terms.
- Using another company's JAN code for your own or a different product, or creating a new ASIN with a barcode bought from a third party: this counts as false product identification information and can lead to suspension or removal of your privileges (listing a genuine, already-registered product using the JAN code that actually belongs to it is fine).
- Running "Delete Product and Listing" before reading the notification: it can't be undone.
- Remapping a restricted ASIN's SKU to an unrestricted ASIN: Help identifies this as a violation.
- Altering or fabricating documents or images before submitting them: the Seller Code of Conduct prohibits misleading conduct, including in communications with Amazon. Submitting altered materials is a violation of the terms and can lead to more serious consequences, including suspension. If you can't produce a document, explain the situation honestly instead.
Registration rules and tool practices to prevent a repeat
Checklist for registration and tool management
- Did you search by product code, brand name, model number, and product name before creating a new listing?
- Can you explain your reason for using a separate ASIN, based on the decision table above?
- Is the product code one you own or are authorized to use, and does it match your GS1 registration and brand name?
- Have you settled on a single method for updating any given SKU?
- Are changes to your submission settings recorded, and are your processing reports saved?
- Do you periodically review which employees and service providers have access?
The basics for preventing duplicates come down to three things: search before you create, use a single channel for submissions, and keep records. Write your procedure down so it survives a change in who's responsible.
Frequently asked questions
Q. If a tool created the ASIN automatically, is it still my responsibility?
A. Under the Amazon Services Business Solutions Agreement's Selling Partner API terms, actions taken using your account ID and credentials, including by a third party, are your responsibility as the seller.
Q. Is having multiple of my own SKUs on the same ASIN also a duplicate?
A. That's a separate issue from ASIN duplication. That said, Help states that when multiple SKUs list against the same ASIN, the attribute values must match across all of them, and any change must be applied to every SKU.
Q. Two similar products appear split into separate variations, or child ASINs look duplicated — what then?
A. Improper splitting of a variation family, or "duplicate (shadow) ASINs" — visually identical child ASINs sitting within the same variation family — are treated as separate issues from the ASIN duplication covered here. Help calls the situation where multiple variation families are created inaccurately for what is really the same model a "split variation" and treats it as a listing policy violation. Sellers can't remove a child ASIN from a variation themselves, so describe the specific situation and contact Amazon Technical Support.
Q. Is a duplication violation treated as minor?
A. Check the severity shown in your notification and in Account Health (アカウント健全性). Your account can be suspended if violations of the same policy reach the limit within 180 days.
Q. Our packaging changed. Do we need a new ASIN?
A. If the product inside is unchanged and only the packaging color, design, or material changes, a new ASIN generally isn't required. If the product's own materials, function, or size changes, a new ASIN may be needed. Check with the manufacturer about how the JAN code should be handled too.
Q. Error 8571 appeared and I can't create a new ASIN. Is that related to duplication?
A. Error 8571 indicates you've hit the limit on the number of ASINs you can create, and Help states that one purpose of this limit is to prevent duplicate catalog entries. You can still list against existing ASINs while the limit applies, so search for the existing ASIN first.
Summary
- Identify the cause using the three paths above, and check what the Performance Notification actually asks you to do first
- Keep records before you delete anything. A violation entry isn't removed just because you delete the SKU
- Search by product code, brand name, and model number before creating a new listing, and stop and check if you get error 8573
- Under the agreement, actions taken through a tool are still your responsibility. Check both what's being sent and how it's being sent
- Use a merge or split request, or contact Technical Support, to resolve the duplication
A single duplicate can sometimes point to a shared cause in your registration process or tool settings. If you're not sure how to proceed, organize your records and consider consulting a professional as well.
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