# Expressions in audiences

You can access and use the expressions builder via Orbit audiences. Expressions provide a powerful way of further manipulating source data for your audience. The main way to add expressions in audiences is via filters on clauses.

> [!NOTE]
>
> To use expressions in Orbit, you must have the requisite knowledge of how to write expressions.

> [!NOTE]
>
> You can create numeric or text variables, but Orbit audiences don’t yet support date variable expressions.

> [!NOTE]
>
> For more context around building and using expressions, see the [FastStats help content for expressions](<https://help.apteco.com/en/faststats/expressions/index.md>).

## Adding an expression to an audience

> [!NOTE]
>
> **Example use case**
>
> The expression used below is very simple for illustrative purposes. A more complex example would be for UKPostcodeDistMin, where you could reference the systems postcode variable to get the nearest store:
>
> `UKPostcodeDistMin(\[Postcode\], "SW1A 1AA","EH99 1SP", "CF99 1NA")`
>
> If you used the UKPostcodeDistMin expression outlined above, it would produce a numeric output and therefore you could select people in a household that were within say 20 miles of the nearest store.

To add an expression to an audience:

1. Go to **Audiences**.
2. Open or create an audience.
3. Click **\+ Add Filter**.
4. Select the **Expression** tab.
5. Enter a **Name** and select a **Table** from the dropdown menu.
6. Write your **Expression** and click **Apply**.

   A variable representation of your expression is now displayed. In this example, it’s a text variable representation of booking destinations that is shown.
7. From the **Values**, **Existing File**, or **Upload File** tab options, supplement your expression with further detail and click **Apply**.

Your audience now includes the number of people defined by the value of your applied expression.