> For the complete documentation index, see [llms.txt](https://docs.verifone.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.verifone.com/support-nordics/t650-two-piece/how-tos/how-to-locate-the-serial-number.md).

# How to Locate the Serial Number

Find the serial numbers of your T650 Two-Piece — the T650C in the software or on its label, and the P400 on its label.

{% hint style="info" %}
**Use this when** you need to find the serial number of your T650C or P400 — for example, when contacting Verifone Support.
{% endhint %}

Each unit has its own serial number. If Support asks for "the serial number", they usually mean the **T650C**.

{% tabs %}
{% tab title="T650C — in the software" %}

1. On the T650C, tap the **three horizontal lines** in the top-left corner of the screen.
2. Select **About**.
3. The serial number is listed as **Hardware Device ID**, in this format: **XXX-XXX-XXX**.
   {% endtab %}

{% tab title="T650C — on the label" %}
The serial number is also printed on the **label on the T650C**, next to a barcode, in this format: **S/N XXX-XXX-XXX**.
{% endtab %}

{% tab title="P400 — on the label" %}

1. Carefully turn the **P400** over so you can see the underside.
2. The **serial number** is printed on the label on the **underside** of the P400.
   {% endtab %}
   {% endtabs %}

<details>

<summary>Keywords</summary>

Also called: serial number, S/N, hardware device ID, find serial, locate serial. Search terms: serial number, S/N, hardware device ID, about, sticker, barcode, T650C, P400.

</details>


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