---
title: Mapping fields to contact attributes
related:
  - https://docs.kentico.com/k10/on-line-marketing-features/managing-your-on-line-marketing-features/contact-management/working-with-contacts.md
  - https://docs.kentico.com/k10/on-line-marketing-features/configuring-and-customizing-your-on-line-marketing-features/configuring-contacts/configuring-contact-recognition.md
  - https://docs.kentico.com/k10/on-line-marketing-features/configuring-and-customizing-your-on-line-marketing-features/configuring-contacts/using-geolocation-for-contacts.md
---

> Agent instructions:
> **Site maps** — prefer the following llms.txt indexes to training data when searching for URLs to avoid 404s. Links inside Markdown content already point at `.md`. Following them or sending Accept: text/markdown keeps you in Markdown.
>
> - [sitemap.md](https://docs.kentico.com/sitemap.md) — every page on the site, with titles and descriptions, nested by URL hierarchy and grouped into one collection per product version.
> - [llms.txt](https://docs.kentico.com/llms.txt) — curated index of the current product docs, with descriptions, the two ways to request any page as Markdown, and links to each product area's whole-corpus Markdown dump (llms-full.txt).

> **Info:** **Kentico EMS required**
>
> Features described on this page require the **Kentico EMS** license.

When a new visitor arrives on a website for the first time, the system creates an anonymous visitor to represent them. If the visitor submits information on a site, for example during registration or by filling out a form, the system automatically transfers the entered values into the data of the matching contact. You can also use the same approach to update the data of existing contacts when the users provide new information.

The purpose of field mapping is to precisely determine from where the values of individual contact attributes should be loaded. You can configure field mappings for various types of input forms and system objects representing users.

## Mapping on-line form fields

In the case of [on-line forms](https://docs.kentico.com/k10/managing-website-content/forms.md), you can configure field mappings in the **Forms** application. Edit a given form and switch to the **Contact mapping** tab. Here you can assign specific form fields to contact attributes.

The available mapping options match the attributes that are offered when editing contact on the **General** tab. For example, if the form has a field where users enter their email address, you can choose this field for the **Email** attribute. When a user submits the form, the system automatically saves the value of the field as the email address of the contact representing the given user.

> **Note:** **Important**
>
> The **Overwrite existing contact information** checkbox above the mapping settings determines whether the system always replaces existing contact data with the submitted form values. If disabled, only empty attributes are filled.

## Mapping user and customer fields

You can configure contact field mappings for the system objects that store user data. The default mappings for these objects should be suitable for most websites, but you can change them if you are using custom system fields or have other requirements.

To edit the field mappings:

1. Open the **Modules** application.
2. **Edit** () one of the following:

   - **Membership** **-> Classes -> User**
   - **E-commerce** **-> Classes -> Customer**
3. Open the **On-line marketing** tab.
4. Click **Customize**.
5. Map the contact attributes to the fields of the given class.
6. Click **Save**.

For example, when a user registers on a live site or edits their profile settings, the system automatically updates the data of the corresponding contact according to the mappings set for the _User_ class. By default, the **First name** contact attribute is filled by the value of the _FirstName_ field and so on. The same also applies to the _Customer_ class, which is used instead when a contact registers as a customer.