External numbers allow you to link items in Xentral uniquely to different numbers from shops, marketplaces, or other systems — making them a central tool for clean processes in multi-channel sales, logistics, and system migrations.
External numbers are alternative item numbers that you can assign to an existing item in Xentral to uniquely identify it in external systems such as online shops, marketplaces, or with customers. They serve as the link between the internal item structure in Xentral and the individual numbering logic of external systems.
In practice, external numbers come into play whenever an item is managed under a different number in an external system — whether it’s an Amazon SKU, a Shopify item number, an EAN code, or a customer item number from a large customer. By mapping this external number to the internal item, you ensure that all processes — from import through stock reconciliation to picking — run correctly.
External numbers are a powerful tool, but should be used in a targeted way with a clear strategy. You should maintain them when:
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you sell items across multiple channels and each channel uses its own numbers (e.g. Shopify, WooCommerce, Amazon),
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you want to connect marketplaces such as Amazon or eBay that require a specific SKU,
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you have large customers who use their own item numbers when placing orders,
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you work in logistics processes with changing EANs or barcodes that differ from the Xentral-internal number (Note: a unique EAN can be stored directly in the item. In this case, no external number is needed).
Caution
External numbers are not required if you only work with one shop system and manage all item numbers centrally and consistently. In this case, it is better to work with identical item numbers in all systems to avoid maintenance overhead.
In brief:
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You use only one shop and manage everything centrally: If you have full control over all item numbers, one consistent number across all systems is sufficient.
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Item numbers in shop, Xentral, and logistics are identical: No mapping needed → no external number required.
Theoretically it would be ideal to use the same item number everywhere. In practice, this often fails for the following reasons:
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Technical restrictions: Shop systems such as Shopify or marketplaces such as Amazon only allow certain formats — no spaces or special characters.
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Variant logic: Variant items are often mapped differently in Xentral, shops, or on Amazon.
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External requirements: Customers or marketplaces insist on their own SKUs or designations.
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EANs or barcodes: As product labels, these frequently differ from the item number but are relevant for logistics processes — for scanning purposes.
The solution is a clean separation: in Xentral you maintain one central item number, and you store system- or customer-specific external numbers as needed.
Note
Correct maintenance of external numbers is essential to avoid overlaps, mix-ups, or incorrect stock bookings. Especially with automated integrations, such as the Amazon connection, error-free external number maintenance is often a prerequisite for smooth operations and correct order processing.
External numbers help you correctly assign items in Xentral even when they are managed under different numbers in other systems. They are particularly useful when working with multiple sales channels, suppliers, or country structures.
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Shops and marketplaces with their own numbers: Many shop systems (e.g. Shopify, WooCommerce) and marketplaces (e.g. Amazon, eBay) use their own item numbers or SKU formats. For Xentral to correctly assign orders or stock reconciliations, you maintain these numbers as external numbers.
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Avoiding constant re-labeling when numbers change: If you sell products whose labels or SKUs change regularly (e.g. due to manufacturer updates, seasonal variants, or external requirements), you can store all numbers as external numbers — so you don’t have to re-label every time.
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Resellers with supplier labels: If you source items from manufacturers or wholesalers who print their own numbers on the packaging, you can store these as external numbers with a supplier reference. This saves you re-labeling while still enabling correct assignment in Xentral — e.g. when scanning in goods dispatch.
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Sales abroad with country-specific numbers: If you sell the same item in different countries under different numbers, you can maintain the respective country-specific item numbers as external numbers. This means you only need one item in the ERP while retaining flexibility for regional requirements (e.g. France: different SKU, different language, different packaging).
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Migration from a legacy system: When switching ERP systems, it can make sense to retain the item numbers from the previous system as archived external numbers. For example, create a project or shop called "Legacy system" and maintain all old numbers there as external numbers — for traceability in returns, service cases, or legacy stock.
In the shop, item assignment is done by default via the SKU. If this differs from the internal item number in Xentral, the assignment is controlled via the maintained external number.
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If the SKU used in the shop does not match the internal item number, the maintained external number ensures unique assignment.
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The label when creating the external number plays a central role, especially in combination with the connected shop connector (Connect).
The external number is maintained in the Item External Numbers module (see above).
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Item: The item managed in Xentral to which the external number is assigned.
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External number: The external item number from the shop or marketplace (e.g. SKU).
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Shop: The shop ID through which the external number is assigned to the correct channel.
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Label: A freely selectable identifier, e.g. sku, ean, supplier_no.
This label must be explicitly configured in the shop connector:
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Enable the Use external numbers option in the connector.
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Enter exactly the same term under Label as was maintained in the external number (case-sensitive).
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Only when label and external number match does Xentral recognize the correct assignment during order import or item reconciliation.
Caution
Using the label is not optional but required, because:
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You can maintain multiple external numbers per item and shop.
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The label serves as a technical selector to distinguish between different types of external numbers.
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Without this information, no unique selection is possible — even with only one external number.
Important in practice:
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Labels such as sku, ean, supplier_sku are common — choose a term that reflects the purpose of the number.
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The label must be maintained identically in both the external number and the connector — otherwise no link is established.
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Use different labels if you want to maintain, for example, both a SKU and an EAN.
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The label is independent of the shop name — it enables additional separation within a single shop.
This allows you to precisely control which external number applies in which context, while retaining the flexibility to systematically manage multiple external numbers for the same item.
Further details can be found in the article Shopware 6 - Processing External Numbers (Connect).
You can create external numbers in Xentral in two ways — manually or via import. Both methods enable unique assignment.
Warning
Use each external number only once (per shop) — duplicate entries or incorrect assignments lead to order import errors and incorrect stock bookings.
This method is suitable when you want to maintain several external numbers quickly.
Steps:
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Navigate via Smart Search to Item External Numbers or alternatively use the path: App store > Master data > Item External Numbers.
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Click on +NEW.
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Select the desired item using the search.
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Enter the external number (e.g. Amazon SKU, customer number, EAN).
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Select the associated channel / shop from the dropdown.
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Optional: Enable Barcode scanner if the number should be scanned during dispatch. Enable Active to use the number immediately.
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Click on Save. The external number is now available in the system and can be used in processes such as ordering, dispatch, or import.
This method is suitable when you are working on a specific item.
Steps:
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Open: Sales > Items > Open item > Tab: External numbers
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Enter the label (e.g. SKU, EAN, customer ID).
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Enter the external number.
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Select the associated channel / shop from the dropdown.
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Enable the Barcode scanner option if needed, when the number should be scanned during dispatch.
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Enable Active to use the number immediately.
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Click on Save. The external number is now available in the system and can be used in processes such as ordering, dispatch, or import.
An import is available for large amounts of data.
Steps:
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Go to: Master data > Import/Export Center > Master data import.
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Select the template 01 J - Shop assignment with external numbers.
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Upload your prepared CSV file: select the CSV file and use UTF-8 as the character encoding. Click on Upload CSV now.
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Make sure that fremdnummerX_shopid is filled in correctly.
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Run the import: check Preview and click on Import.
Note
fremdnummerX_shopid External number for shop with ID shopid
fremdnummerbezeichnungX_shopid Optional label (e.g. SKU, EAN)
Note
You can import up to 40 external numbers (X = 1–40) per item, each with an assigned shop ID. You can find the shop IDs in the overview of all online shops.
Note
Manual setup of the import template: Shop assignment with external numbers:
Settings:
Name: 01 J - Shop assignment with external numbers (by item number)
Target: Item (minimum: number or name_de)
CSV data from row: 2
CSV separator: ;
CSV masking: " (quotation marks)
Character set: UTF-8
CSV fields:
1:nummer;
2:fremdnummer_1;
3:fremdnummerbezeichnung_1;
4:shop_1;
5:aktiv_1;
6:fremdnummer_2;
7:fremdnummerbezeichnung_2;
8:shop_2;
9:aktiv_2;
Note: Replace the digits in the field name (_1, _2) with the shop ID for which the external number should apply (e.g. fremdnummer_4 for shop ID 4). You can find the shop IDs under Administration > Shop interface > Overview.
This allows external numbers for multiple shops to be imported simultaneously — each with the associated label and active status.
You can configure any external number so that it can be scanned in logistics processes — e.g. in the dispatch center during packing or in goods receipt inspection.
Enable the Barcode scanner option in the external number management to do this. Xentral will then automatically include this number when scanning — even if it differs from the internal item number.
Note
Example:
A supplier label shows the number 'EAN-4001234567890', your internal item is called 'TSHIRT001'. If the EAN is stored as a scannable external number, Xentral still identifies the correct item when scanning in the dispatch process — even if a different EAN is also maintained in the item.
External numbers are used in Xentral wherever items need to be recognized and correctly assigned across systems — for example during import, in dispatch, or for customer-specific orders.
When items are imported from a shop or marketplace, Xentral automatically compares the external numbers with existing items. If the numbers match, the item is correctly assigned. If there is no matching external number, incorrect assignments or duplicate entries may occur.
In the dispatch center, employees can scan items using the external number — e.g. via EAN or Amazon SKU — if it is marked as "scannable". In addition, the option Allow scanning of shop external numbers must be enabled in the project.
Practical benefit: Even if the label does not show an internal Xentral item number, the item is correctly identified.
Amazon is a standalone system with the following characteristics:
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You define your SKU when uploading an item to Seller Central — this SKU remains permanently assigned to that item.
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Amazon SKUs are channel- and warehouse-dependent, meaning you need separate SKUs for FBA and FBM, even if it is the same physical item.
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Amazon uses the SKU for internal management, API communication, and order feedback.
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The SKU cannot be changed retroactively — if changes are required, you must create the item again.
Note
When you need multiple Amazon external numbers — typical scenarios:
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You sell the same item as FBA and FBM → two external numbers with different SKUs.
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You use Pan-EU or multiple Amazon marketplaces → different SKUs per country recommended.
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You have multiple listings for variants or bundles → each variant has its own SKU.
Tip
How to work with this in Xentral:
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Maintain the Amazon SKUs in the item as external numbers with the shop assignment "Amazon".
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Use a separate external number for FBA and FBM respectively.
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Use the import function for large numbers of items (Master data import template 01 J).
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Enable the barcode scanner function if needed, when you also use Amazon SKUs in goods dispatch (e.g. for Amazon FBM with your own warehouse).
Note
Automation via the Amazon interface:
If you use the Amazon interface in Xentral, SKU assignments can be created automatically — especially during order imports. Nevertheless, it is recommended to maintain external numbers proactively to avoid later errors and manual rework.
Technically yes, strategically usually no.
Amazon often uses highly structured, marketplace-specific SKUs (e.g. SKU_FBA_RED_XL). These make little sense in a shop — especially from an SEO, user experience, and product range consistency perspective.
Tip
Maintain the Amazon SKU as an external number, but use descriptive, brand-consistent item numbers in your shop.
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Shopify SKU: This is maintained in Shopify but is not technically required — it only serves organizational purposes.
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Handle / slug / URL name: The visible product path is often a different ID.
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Product ID: Internal Shopify ID, not visible but available via API.
Tip
The Shopify SKU can be identical to the Xentral item number — but does not have to be. If different → maintain it as an external number.