# Proxy number usage

You can use a proxy number instead of card ID in many cases.

A proxy number can be printed on the card envelope as a nonsensitive unique identifier of the card and can be used to activate the plastic card once received from the cardholder instead of PAN, CVV and expiration date. There are two reasons why not to use the card ID for card activation:

* it is too long (32 characters)
* it has a very specific format that may not fit with customer requirements.

The power of the Proxy number is the flexibility that NymCard offers to the customer to define the length and the format. For example, one client asked for 9 digits proxy number that does not start with 0. We are open to any other format as well.<br>


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.nymcard.com/get-started/issuing-physical-cards/proxy-number-usage.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.