# Define units and barcodes

> Add a unit conversion (carton, box) to a product card and define a product barcode or generate an in-house barcode.

URL: https://erpdocs.corexlogic.com/en/stok/islemler/birim-ve-barkod-tanimlama

- **Type:** Task
- **Module:** Inventory
- **Menu path:** Ana Veriler › Ürünler › Ürün Ana Verileri › ürün detayı › Birimler · Barkodlar (Master Data › Products › Product Master Data › product details › Units · Barcodes)
- **Screen route:** `/erp/catalog/products/{id}`
- **Required permission:** `erp-catalog-items.edit`, `erp-catalog-units.view`
- **Prerequisites:**
  - The unit to be added is active in **Ölçü Birimleri** (Units of Measure) (e.g. KUTU, KOLI).

Stock is always kept in the card's **base unit**; a quantity entered in another unit is converted using the
card-specific conversion. A barcode identifies the product and its unit.

## Steps

1. Open the product details (e.g. **MAM-0008 SIVI DETERJAN 5 LT**) and switch to the **Birimler** (Units) tab.
   <!-- action: open · target: "Birimler" -->

   ![Product detail — Units tab](https://erpdocs.corexlogic.com/en/en/img/screens/stok/urun-birimler.png)
   1. Add Unit — new conversion
   2. Rate — base units per unit

2. Click **Birim Ekle** (Add Unit). Enter the **Kaynak Birim** (Source Unit) (e.g. KUTU), the **Hedef Birim** (Target Unit) (the base unit, e.g. ADET) and the **Çarpan** (Factor) (how many target units one source unit equals), then click **Kaydet** (Save).
   <!-- action: click · target: "Birim Ekle" · value: "1 KUTU = 4 ADET" · expect: "The unit appears in the table with Temel (Base) and Oran (Ratio)" -->
3. Switch to the **Barkodlar** (Barcodes) tab. To add a barcode you already have, click **Barkod Ekle** (Add Barcode); for an in-house number, click **Barkod Üret** (Generate Barcode).
   <!-- action: open · target: "Barkodlar" -->

   ![Product detail — Barcodes tab](https://erpdocs.corexlogic.com/en/en/img/screens/stok/urun-barkodlar.png)
   1. Add Barcode — scan or type
   2. Generate Barcode — in-house EAN-13
   3. Print Labels for Selected

4. In the **Barkod Ekle** (Add Barcode) window, scan or type the **Barkod** (Barcode), enter the **Birim** (Unit) the barcode belongs to (a carton barcode with the carton unit) and an optional **Açıklama** (Description), then click **Ekle** (Add).
   <!-- action: fill · target: "Barkod" -->
5. To print labels, select the barcodes and click **Seçilenlerin Etiketini Bas** (Print Labels for Selected).
   <!-- action: click · target: "Seçilenlerin Etiketini Bas" -->

**Result:** A unit with a defined conversion can be selected on sales, purchasing and inventory forms; the quantity is converted to the base unit when it is posted. When the barcode is scanned, the product and the unit are filled in together.

## What you need to know

- The reverse direction of a conversion is not defined separately (1/factor). A second conversion between the
  same two units is rejected: "Bu iki birim arasında ters yönde bir dönüşüm zaten tanımlı." (A conversion in the
  reverse direction between these two units is already defined.)
- On a saved conversion, only the factor can be changed (**Oranı Düzelt** (Correct Ratio)); past movements are not
  affected.
- A conversion must be defined for the barcode's unit first: "Barkodun birimi kartın temel birimi ya da birim
  dönüşümlerinden biri olmalı. Önce Birimler sekmesinden dönüşümü tanımlayın." (The barcode's unit must be the
  card's base unit or one of its unit conversions. Define the conversion on the Units tab first.)
- A barcode can be defined on only one card: "'\{barkod\}' barkodu '\{kart\}' kartında tanımlı." (Barcode
  '\{barkod\}' is defined on card '\{kart\}'.)
- A warning appears for a barcode that looks like a GS1 number but whose check digit does not match; if you are
  adding it deliberately, click **Yine de Ekle** (Add Anyway).
- **Barkod Üret** (Generate Barcode) produces an in-house EAN-13 starting with "20". You can also select several
  cards in the list and run **Barkod Üret** in bulk; cards that already have a barcode, non-stock cards and
  configurable parent cards are skipped.

## Related

- [Product master data › Units](https://erpdocs.corexlogic.com/en/stok/ekranlar/urun-ana-verileri#birimler)