# NFC Write Tag

Uses the device NFC antenna for writing data from HF tags when in close proximity.

Action available for the following operating systems:

![](/files/kfMeq0OanEe5OOx5RmUn)

### Parameters

* **Tag Type** numeric - The type of tags to write data. It can be one of:
  * 1 - **Mifare Classic**
  * 2 - **Mifare Ultralight**
  * 3 - **ISO 15693**
* **Coded** numeric - Specifies if the data to write is coded with ASCII codes enclosed in ‘<’ and ‘>’. This is useful for debugging. It can be one of:
  * 1 - **Yes**
  * 2 - **No**
* **Block Index** numeric - Block index to read.
* **Data** string - The data to write into the tag block. It should be a multiple of the block size. If it is not, Kalipso will try to read the current content of the block before writing to change only the needed data, but it will be a slower operation.

{% hint style="info" %}
On iOS currently read/write is only supported for ISO 15693
{% endhint %}


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