> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lekalao.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Contact fields

> What you know about the people you write to, and what kind of value each thing is.

An e-mail address, a first name and a last name come with every subscriber. Everything else you know — a birthday, a plan, a number of orders — is a **contact field**. A field has a **type**, and the type is what makes it useful: a date compares as a date, a number as a number.

Fields belong to the team, not to a list: the person is the same whichever list they are on.

## Create a field

<Frame caption="The fields of the team, each with its key and its type.">
  <img src="https://mintcdn.com/lekalao/L23y78v0n8Vzliow/images/en/contact-fields.png?fit=max&auto=format&n=L23y78v0n8Vzliow&q=85&s=26f1d4e7d78202a96ecd1ce880d5a9d8" alt="The contact fields page" width="1520" height="980" data-path="images/en/contact-fields.png" />
</Frame>

**Settings → Contact fields → New field.**

<ParamField path="Name" type="text" required>
  What people see: in the import screen, the segment builder, the sign-up page.
</ParamField>

<ParamField path="Key" type="letters, numbers, . _ -" required>
  What templates and the API call it: `{{ subscriber.attributes.birthday }}`. It never changes afterwards.
</ParamField>

<ParamField path="Type" type="Text, Number, Date, Yes or no" required>
  How values are kept and compared.
</ParamField>

| Type          | Kept as                 | What it allows                                                                                                       |
| ------------- | ----------------------- | -------------------------------------------------------------------------------------------------------------------- |
| **Text**      | the words as given      | equals, contains                                                                                                     |
| **Number**    | a number (`12`, `12.5`) | greater than, less than — in [segments](/contacts/segments) and in [conditions](/content/personalization#conditions) |
| **Date**      | `2026-05-12`            | before, after, and the trigger [A date of the subscriber comes round](/automations/triggers)                         |
| **Yes or no** | `true` or `false`       | is, is not. `yes`, `oui`, `1`, `true` are all read as yes                                                            |

A value that cannot be read as its type — "soon" in a date — is not lost: it is kept as it was given, and simply matches no comparison of that type. Dates are read in the usual forms (`2026-05-12`, `12/05/2026`) and kept as `2026-05-12`.

<Tip>
  You do not have to declare every field first. A value that arrives under an unknown key — from an import, the API or a form — creates a **Text** field of that name by itself. Give it its real type afterwards.
</Tip>

## Change the type

Changing a field from Text to Date rewrites, in the background, what every contact holds under that key into the new shape. A value that cannot be read as the new type is left as it was. The **Contacts with a value** column says how many people the field is known for.

## Remove a field

The field is no longer offered in forms, imports and segments. What contacts hold under its key is kept: create the field again and the values are there.

## Where fields are used

* **Imports**: a column of your file is matched to a field. See [Import and export](/contacts/import-export).
* **The sign-up page**: you choose which fields it asks. See [Pages and pop-up](/contacts/pages-and-popups).
* **Segments**: "birthday is before…", "orders is greater than 3". See [Segments](/contacts/segments).
* **E-mails**: `{{ subscriber.attributes.plan }}`. See [Personalization](/content/personalization).
* **The API**: `attributes` on a subscriber, and [`/v1/fields`](/api-reference/introduction) to manage the fields themselves.