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# Loyalty card validation via POS

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This article explains how to validate a loyalty card via a Point of Sales (POS) system. The process involves finding users in the loyalty program and adding a stamp to their loyalty card using Coupontools API.

**Step 1: Find the user**

To validate a loyalty card in your POS, you need to use the [Get All Stats API](https://docs.coupontools.com/api/v4/loyalty#get-all-stats) to research for a user by its name and retrieve their loyalty card. 

![](https://storage.crisp.chat/users/helpdesk/website/4c4cc617dc0a0c00/schermafbeelding-2025-02-10-09_cmtmmn.png)
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**Step 2: Adding a stamp to the loyalty card**

Once you have identified the user, you can add a stamp to their loyalty card. Use the [Add Stamp API](https://docs.coupontools.com/api/v4/loyalty#add-stamps) to assign a stamp to the identified loyalty card.

![](https://storage.crisp.chat/users/helpdesk/website/4c4cc617dc0a0c00/schermafbeelding-2025-02-10-09_1b6o1tx.png)

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