> For the complete documentation index, see [llms.txt](https://knowledge.out-smart.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://knowledge.out-smart.com/backoffice/backoffice/items-and-materials/use-item-codes.md).

# Use item codes

Learn how item codes work, when to change them, and what to avoid.

Every item needs an item code.

OutSmart uses this code as the main identifier for the item across the catalog, imports, and integrations.

### How item codes work

An item code can contain numbers, letters, or both.

The code must be unique.

Once an item is in use, changing the code can break matching in imports, automations, and integrations.

### Best practices

Use item codes that are:

* unique
* stable over time
* compatible with connected systems

Avoid special characters when possible. Some integrations do not accept them.

### Set an item code

{% stepper %}
{% step %}

### Create or open the item

Go to **Items**.

Open an existing item or create a new one.
{% endstep %}

{% step %}

### Enter the code

Fill in **Item code**.

Use a value that fits your current catalog structure.
{% endstep %}

{% step %}

### Save the item

Save the item.

The code is now used as the item identifier.
{% endstep %}
{% endstepper %}

### Change an item code

You can change an existing item code, but only do this when necessary.

Changing a code can cause duplicate items, import mismatches, or integration errors.

{% hint style="warning" %}
Do not change item codes casually. Existing data may no longer match the updated code.
{% endhint %}

### When a code change causes problems

Problems usually appear when:

* an import file contains new codes for existing items
* an integration accepts a stricter code format
* employees can still select old and new versions of the same item

If you must switch to a new code format, update the full catalog in a controlled way.

### Frequently asked questions

<details>

<summary>Can I use letters in an item code?</summary>

Yes. OutSmart accepts letters, numbers, or a combination of both.

</details>

<details>

<summary>Can I change an item code later?</summary>

Yes. But only do this when it is required.

</details>

<details>

<summary>Why do integrations matter?</summary>

Some integrations accept fewer characters or only certain formats. Your item codes must match those rules.

</details>

### Related topics

* [**Create an item**](/backoffice/backoffice/items-and-materials/create-an-item.md)
* [**Import items from Excel**](/backoffice/backoffice/items-and-materials/import-items-from-excel.md)
* [**Understand item fields and options**](/backoffice/backoffice/items-and-materials/understand-item-fields-and-options.md)


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