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Item Number Ranges and SKU (Item Categories Module)

  • Updated

Item number ranges in your ERP system are highly beneficial and offer you key advantages for organizing and managing your business:

  • Systematic organization: Item number ranges allow you to organize your products methodically and systematically. Each product receives a unique item number, making it easier to identify and locate items in your system. This is particularly useful when you manage a wide range of products or variants.

  • Simplified order processing: In the sales process, unique item numbers simplify order processing by helping to avoid misunderstandings and errors during ordering. Clear item numbers reduce the likelihood of incorrect deliveries and increase customer satisfaction.

  • Support for multi-channel sales: In today’s environment, where you often sell your products across multiple channels, unique item numbers ensure consistency and integrity of product information across all sales channels.

  • Support for compliance and traceability: In regulated industries such as pharmaceuticals or food production, product traceability is essential. Item number ranges facilitate compliance with regulatory requirements and support effective recalls and quality controls.

  • Adaptability and scalability: Item number ranges can be designed to respond flexibly to changes in your product portfolio or business expansions. They can be extended or modified to accommodate new product lines or categories.

Why you should use good item number formats

  • Improved efficiency in logistics: In logistics, clear and easily readable item numbers speed up the locating and processing of goods. This is particularly important when picking, packing, and shipping products. Clear item numbers reduce the likelihood of errors that could lead to incorrect deliveries and accelerate the overall logistics process.

  • Better error detection and prevention: When item numbers are unique and easy to read, employees can quickly identify and correct errors. This applies to stock discrepancies, duplicate entries, and other inventory management problems that can occur when item numbers are difficult to decipher.

  • Faster customer service: In customer service, clear item numbers facilitate communication with customers. Service staff can respond quickly and efficiently to enquiries about product availability, order status, and other customer-specific questions. This leads to improved customer satisfaction, as issues can be resolved more quickly and overall service quality is raised.

  • Support for automated systems: In modern warehouse and ERP systems that use barcodes and RFID technology, clear item numbers facilitate the automation of processes. Barcode scanners and other automated capture systems are less prone to read errors when item numbers are clear and legible.

  • Training and onboarding: For new employees, it is easier to familiarize themselves with a system of clear and logically structured item numbers. This shortens the onboarding period and minimizes the risk of errors in the early stages of employment.

  • Standardization and scalability: Clear and standardized item numbers facilitate the scaling of business operations. They enable consistent handling of inventory and orders across different locations and departments, which is particularly important for growing companies.

Excursus: Guidelines for Creating Item Number Formats

When creating item number formats in an ERP system, you should use a clear, systematic, and standardized schema that makes it easy to uniquely identify items, supports efficient data capture, and avoids processing problems. Here are some guidelines to help you create effective item number formats:

  • Maintain consistency: Choose a uniform format that is applied to all item numbers. This could be a combination of letters and numbers, such as "A100000", or a prefix-based format such as "FP-10000" that can reflect the item’s category.

  • Avoid date-like formats: Avoid formats that could be misinterpreted as dates, such as "8400-45-22" or "12-45-1000". These can lead to confusion in data processing and analysis.

  • Do not use spaces or special characters: Spaces and special characters such as periods or slashes can cause problems with data entry, barcode scanning, and software integration. Check in advance, for example, which numbers you want to use at the packing station. You can also scan the EAN if the number format cannot be changed — however, keep in mind the additional data maintenance or import effort this involves.

  • Ensure barcode compatibility: Item numbers should be chosen so that they can easily be converted into barcodes or QR codes. Avoid complicated or overly long numbers that could impair barcode readability.

  • Plan for future-proofing and scalability: Make sure that the chosen numbering system provides enough room for future expansions. A number range that is too narrow can quickly reach its limits when your product portfolio grows.

Note

What to avoid:

  • Long and complex sequences: Number sequences that are too long can be problematic when printing labels or scanning.

  • Dynamically changing formats: Avoid frequently changing the number format, as this can lead to inconsistencies in data capture and inventory management.

Caution

Practical recommendations:

  • Keep internal item numbers unique — this prevents matching conflicts and incorrect assignments. Do not create duplicate item numbers!

  • Store deviating numbers from external systems as external numbers: In the item master data > tab External numbers, create an entry for each reference to maintain clean links to other systems.

Creating Item Categories

Tip

Video tutorial: Your quick start to creating item categories

Would you like to get an overview of creating and using item categories in Xentral in just a few minutes? Then our video tutorial is exactly what you need. Watch it now!

You can open the Item Categories module via Smart Search.

In the Item Categories module, in addition to your system number ranges, you can create additional categories for your product range and override the Xentral default with your own categories. The function allows you to select a category when creating new items. On saving, the new item is automatically assigned to this category and receives the next available sequential number from that item category.

Note

You can also have items created in Xentral via a data import or your shop system. When importing data, you can either specify a fixed item number and category, or have the number assigned automatically and then adjust the starting value to the next number in the Item Categories module.

In Xentral, item numbers can be assigned in different ways:

  1. Number range per category: A separate number range per product category.

    Each item category can have its own number range that does not overlap with others, starting with its own sequential first number. This means that every new item in the category receives a sequential number based on that category’s number range.

  2. Central number range: A single sequential number for ALL products regardless of category.

    Here, a sequential number is assigned system-wide for all items, stored in the main number range under the basic settings. If items are to be grouped by categories, the assignment can be taken from the central number range by leaving the item category without a specific number, so the next sequential number is taken from the central range.

  3. Combination of category identifier and central number: A sequential number independent of category, but with a different prefix as an identifier for the product group.

    A prefix (e.g. a sequence of letters) can be defined for item categories, which is combined with the sequential central number when assigned. This allows items to be uniquely identified by category while maintaining a system-wide sequential numbering.

You can open the Item Categories module via Smart Search.

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Note

You can easily define the number range from which your item numbers are assigned in the Next item number text field. Both simple numbers such as "30001" and combinations of letters and numbers are supported. The only requirement is that the item number ends with a numeric block that can be incremented — and this block is increased by one with each new item number.

Note

When you create your own item categories for the first time, the preset Xentral example categories are automatically removed. These templates were only test data and served as a reference to help you create your own categories later.

Creating a New Item Category (SKU Number Range)

Warning

Note that SKUs must not contain spaces. Also make sure to follow our additional guidelines for creating item number ranges.

Steps for Number Range per Category

Follow these steps to create a new product category for your range.

  1. Click on +NEW.

  2. Enter the Name, ideally the category name followed by the starting number in brackets — this way you immediately know which number range is selected when saving a new item. E.g. 'Fresh Produce (FP-01000)'.

  3. Enter the Last assigned item number. When you create a new item in this category, this 'number +1' is inserted as the next item number and the counter is automatically incremented by one. E.g. 'FP-01000'.

  4. Click on Save to create the item category.

You can now create the next category directly via +NEW.

Alternatively: Click on the back arrow to return to the overview and view all item categories. From here you can also create a new item category by clicking on + NEW.

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Tip

The default categories should be sufficient for most purposes. Set up your number ranges pragmatically and avoid using too many unnecessary special settings or numbers when they are not actually needed. You should mainly ensure that the number range:

  • has enough digits (the numeric block at the end of the item number sequence) for a period of 6–18 months

  • is easy for your team to remember and understand

  • has a similar number structure for category groups and/or stocked items, so that it is possible to quickly scan multiple numbers visually, side by side or one below the other, without having to think about it.

Steps for a Category from the Central Number Range

If you want to use the sequential item number from your system’s default number range for an item category, proceed as follows.

  1. Click on +NEW.

  2. Enter the Name, ideally the category name followed by the starting number (from the central number range) in brackets — this way you immediately know which number range is selected when saving a new item. E.g. 'Shop Items (1000000)'.

  3. Click on Save to create the item category.

When you create a new item in this category, the number from the central number range (= system number range) 'number +1' is inserted as the next item number and the counter is automatically incremented by one. E.g. '1000001'.

Note

If multiple item categories access this central number range, the next available number from the central range is assigned for each new item in any of those categories. This means that items in different categories also receive sequential numbers from the system settings. E.g. 1000000, 1000001, 1000003 — where 1000001 may be from the category 'Shop Items' and 1000002 from the category 'Miscellaneous'.

Note

If you additionally specify a project, the category naturally accesses the number range of that project. For example, you can use this approach to assign internal office items or miscellaneous items in categories to different projects and thus different branches. Make sure to maintain a clean separation using prefixes in the number range. For example, you can use 'MUC-1100000' for the Munich branch and 'AUG-1200000' for the Augsburg branch.

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For the Use central number range setting, the number is drawn sequentially from the system number range and used alternately for these item categories.

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Steps for a Category with Identifier Combined with the Central Number Range

If you want to use the sequential item number from your system’s default number range for an item category and additionally add a prefix for that specific category, proceed as follows.

  1. Click on +NEW.

  2. Enter the Name, ideally the category name followed by the prefix and starting number in brackets — this way you immediately know which number range is selected when saving a new item. E.g. 'B2B Items (B2B-1000000)'.

  3. In the Last assigned item number field, enter a prefix, e.g. 'B2B-'. This prefix is used for every number from this category that is automatically generated via "Save item".

  4. Click on Save to create the item category.

When you create a new item in this category, the number from the central number range (= system number range) 'number +1' is inserted as the next item number and the counter is automatically incremented by one. E.g. 'B2B-1000001'.

Note

If you use multiple categories with this function, you get results such as A10000, A10001, B10002, C10003, C10004, C10005, and so on.

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The prefix can also be used for a specific project.

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Settings (Fields) for Item Categories in Xentral

The following fields are available when creating your item category. You should always fill in these mandatory fields:

Name and Last assigned item number.

Settings

Name

Entry via text or search field for the supplier address or supplier number from master data. Address and payment data are loaded via Apply.

Last assigned item number

Invoice number of the incoming invoice. This number is assigned by your supplier’s ERP system. It serves as a reference number in accounting for matching the PDF document, the posting, and the payment booking on your bank account.

Use central number range

Checkbox: the Last assigned item number field can be used as a prefix for the new number. The number from the central number range (from company settings) is appended to this character sequence (e.g. MODULE100001 → MODULE would be the prefix, 100001 the number from the central number range. If the prefix is left blank, the next central number is simply assigned for each item category.)

Project

Optional: restriction to a project, e.g. for user permissions and separation of branches by project.

Export Chart of Accounts

Export Chart of Accounts

Optional: use this when a different chart of accounts should or must be applied to items in this category.

Revenue:

  • Domestic (standard),

  • Domestic (reduced),

  • Domestic (tax-exempt),

  • Intra-community EU (with additional tax text field),

  • EU (standard),

  • EU (reduced),

  • Export (with additional tax text field).

The same applies to expenditures.
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Assigning a Category to an Item

Creating a New Item, Assigning It to a Category, and Assigning a New Number

You can assign an item category including a number to an item by creating a new item, selecting the category, entering the item name, and clicking on Save.

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The item is automatically assigned the next available number from your selected category as its item number.

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Assigning a New Category to an Existing Item

You can assign a new category to an item at any time by selecting the new category and clicking on Save.

The item number is not reassigned — the already assigned number remains in place.

If you do want to change it, you can clear the item number field with your cursor, select the new category, and click on Save. A new category including a number from the new number range is assigned. The old item number no longer exists.

Warning

Do not manually change item numbers if you are using automatic number assignment. Otherwise you will not get a clean number sequence.

When overwriting existing items, consider whether you want to retain an item history or statistics. Unless you are correcting an error, you should set the item to inactive. This preserves the correct statistics for financial reporting while ensuring that the item can no longer be added to documents or stocked.

Editing or Deleting an Item Category

You can also rename an item category if the terminology for your product range changes over time. Consider what history you want to retain. When you rename a category, the new name is displayed in the relevant items and in the selection.

You can also delete a category. Make sure there are no items left in the item category before doing so. To delete a category, click on the X icon in the overview.

Number range changes, such as extending the item number range by additional digits, can be made. Make sure there are no overlaps with other number ranges. Existing items are not changed in their format.

Translating an Item Category

You can translate an item category into another language using the Item Tree function.

Using the Item Category and Item Tree

You can display an item tree for your categories in Xentral:

The Item Tree module allows you to create a structured overview of all items by using main item categories and subcategories. It displays all existing item categories that you have created in the Item Tree and Item Categories modules. You can also use the Name field to search specifically for item categories or subcategories and gain insight into the relationships between items.

Example Item Numbers for Various Industries and Product Ranges

Item Categories for the Food & Beverage Product Range

Main category: Food & Beverage

  • Subcategories:

    • Fresh Produce

      • Fruit

      • Vegetables

      • Refrigerated goods

    • Bakery Products

      • Breads and rolls

      • Sweet baked goods

    • Meat & Fish

      • Packaged meat

      • Packaged fish

    • Beverages

      • Water

      • Juices

      • Soft drinks

    • Dry Goods & Canned Products

      • Pasta

      • Canned goods

      • Ready meals

For a company in the food sector, the structure of item number ranges could be designed to cover a wide range of product categories, ensuring clear and systematic organization and easy product identification. Here is an example:

Item number range name: Fresh Produce

  • Item number: FP-01001 for Apples

  • Item number: FP-01002 for Lettuce heads

  • Item number: FP-01003 for Fresh milk

Item number range name: Bakery Products

  • Item number: BW-02001 for Wholegrain bread

  • Item number: BW-02002 for Croissants

  • Item number: BW-02003 for Donuts

Item number range name: Meat & Fish

  • Item number: FF-03001 for Beef steak

  • Item number: FF-03002 for Chicken breast fillet

  • Item number: FF-03003 for Salmon fillet

Item number range name: Beverages

  • Item number: GT-04001 for Mineral water

  • Item number: GT-04002 for Apple juice

  • Item number: GT-04003 for Red wine

Item number range name: Dry Goods & Canned Products

  • Item number: TK-05001 for Spaghetti

  • Item number: TK-05002 for Rice

  • Item number: TK-05003 for Canned tomatoes

In this example, each item number starts with a unique prefix that encodes the category (e.g. "FP" for Fresh Produce, "BW" for Bakery Products), followed by a sequential number. This structure not only makes it easier to quickly identify and assign products to their respective categories, but also supports efficient inventory management, ordering, and sales processes in the ERP system.

Item Categories for the Home & Garden Product Range

Main category: Home & Garden

  • Subcategories:

    • Kitchen Supplies

      • Small appliances (toasters, coffee machines, blenders)

      • Cookware & bakeware

    • Home Accessories

      • Decoration (pictures, vases, candles)

      • Lighting (lamps, light fixtures)

    • Garden & Leisure

      • Garden furniture

      • Grills & accessories

      • Plants & garden tools

For the main category "Home & Garden" and its subcategories, well-structured item number formats with more than seven digits could look as follows:

Main Category: Home & Garden

  1. Kitchen Supplies

    • Item number: HG-KB-1000001 – for general kitchen supplies

    • Small Appliances

      • Item number: HG-KB-KG-2000001 – Toasters

      • Item number: HG-KB-KG-2000002 – Coffee machines

      • Item number: HG-KB-KG-2000003 – Blenders

    • Cookware & Bakeware

      • Item number: HG-KB-KB-3000001 – Pots

      • Item number: HG-KB-KB-3000002 – Pans

      • Item number: HG-KB-KB-3000003 – Baking trays

  2. Home Accessories

    • Decoration

      • Item number: HG-WA-DE-4000001 – Pictures

      • Item number: HG-WA-DE-4000002 – Vases

      • Item number: HG-WA-DE-4000003 – Candles

    • Lighting

      • Item number: HG-WA-BE-5000001 – Lamps

      • Item number: HG-WA-BE-5000002 – Light fixtures

  3. Garden & Leisure

    • Garden Furniture

      • Item number: HG-GF-GM-6000001 – Garden chairs

      • Item number: HG-GF-GM-6000002 – Garden tables

    • Grills & Accessories

      • Item number: HG-GF-GZ-7000001 – Grills

      • Item number: HG-GF-GZ-7000002 – Grill accessories

    • Plants & Garden Tools

      • Item number: HG-GF-PG-8000001 – Plants

      • Item number: HG-GF-PG-8000002 – Garden tools

These formats use a clear and systematic structure that makes it possible to precisely categorize and extend item numbers. The use of prefixes (such as HG for Home & Garden) followed by further prefixes for subcategories and a sequential seven-digit number provides high granularity and scalability for future product line expansions.

Item Categories for the Electronics Product Range

Main category: Electronics

  • Subcategories:

    • Consumer Electronics

      • Audio & Hi-Fi (headphones, speakers, hi-fi systems)

      • TV & Video (televisions, projectors, Blu-ray players)

    • Computers & Accessories

      • Laptops & desktops

      • Monitors & displays

      • Storage media (hard drives, USB sticks)

    • Smartphones & Tablets

      • Smartphones

      • Tablets

      • Accessories (cases, chargers)

    • Home Electronics

      • Kitchen appliances

      • Household appliances

      • Smart robots

For an electronics company, item number ranges could be structured both by product type and product category to ensure systematic organization and product identification. Here is an example of such a structure, including item numbers and item number range names:

Item number range name: Consumer Electronics

  • Item number: UE-10001 for Headphones

  • Item number: UE-10002 for Bluetooth speakers

  • Item number: UE-10003 for Smart TVs

Item number range name: Computers & Accessories

  • Item number: CA-20001 for Laptops

  • Item number: CA-20002 for Desktop PCs

  • Item number: CA-20003 for External hard drives

Item number range name: Smartphones & Tablets

  • Item number: ST-30001 for Latest-generation smartphones

  • Item number: ST-30002 for Tablets

  • Item number: ST-30003 for Smartphone cases

Item number range name: Home Electronics

  • Item number: HE-40001 for Microwaves

  • Item number: HE-40002 for Robot vacuum cleaners

  • Item number: HE-40003 for Fully automatic coffee machines

Each item number range name represents a specific category of products. The item numbers within each range start with a unique prefix that encodes the category (e.g. "UE" for Consumer Electronics, "CA" for Computers & Accessories), followed by a sequential number that identifies the specific product within the category. This structure makes it easier to identify product categories, organize inventory, and supports precise sales and inventory reports.

Item Categories for the Hardware and Production Product Range

Main category: Hardware and Production

  • Subcategories:

    • Circuit Boards (PCBs)

      • Standard PCB

      • Multilayer

      • Prototype PCB (product development)

    • Finished Circuits (sales)

      • Hardware components

      • Power supply

      • Complete sets

      • Machine assembly of series

    • Industrial Circuits

      • Controllers

      • Complete sets incl. housing

    • Prototype Development

      • Standard components

      • Individual small series

      • Small series with CE certification

For a hardware company specializing in the manufacture of circuit boards and the distribution of finished circuits, it is essential to establish a clear and systematic item number structure. This structure should not only reflect the type of product, but also include information about the specification and possibly the target application. Here is an example of such an item number structure:

Item number range name: Circuit Boards (PCBs)

  • Item number: LP-00101 for Single-layer circuit board, standard

  • Item number: LP-00201 for Double-layer circuit board, standard

  • Item number: LP-00301 for Multilayer circuit board, high-end

Item number range name: Finished Circuits for Consumer Electronics

  • Item number: FC-CE101 for Audio amplifier circuit, standard

  • Item number: FC-CE102 for Power management circuit for smartphones

  • Item number: FC-CE103 for LED driver board, high-brightness

Item number range name: Industrial Circuits

  • Item number: IS-10101 for PLC (Programmable Logic Controller) module, standard

  • Item number: IS-10201 for Temperature control circuit, industrial grade

  • Item number: IS-10301 for Motor control board, heavy-duty

Item number range name: Prototyping & Development

  • Item number: PE-20101 for Breadboard-compatible prototype board

  • Item number: PE-20201 for Microcontroller development board, universal

  • Item number: PE-20301 for FPGA (Field-Programmable Gate Array) development kit, advanced

In this example, each item number starts with a unique prefix that encodes the product category (e.g. "LP" for circuit boards, "FC" for finished circuits), followed by a category code indicating the specific application or quality level (e.g. "CE" for Consumer Electronics, "IS" for Industrial Circuits), and ends with a sequential number. This structure allows the company to efficiently organize its products, maintain a clear overview, and meet the specific needs of different customer groups.

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