# Uppercase()

Returns the provided string using only uppercase letters.

## Availability

<table>
  <tr>
    <td>Marketing Cloud Engagement</td>
    <td>✅ Yes</td>
  </tr>
  <tr>
    <td>Marketing Cloud Next</td>
    <td>✅ Yes</td>
  </tr>
</table>

This function became available in Marketing Cloud Next during the Summer ’26 release (API version 67.0).

## Syntax

```
Uppercase(sourceString)
```

The `Uppercase()` function has one parameter:

- `sourceString` (string): Required. The string to convert to uppercase.

## Usage

To use the function, pass it a string.

```
%%[
  Var @externalCustomerId
  Set @externalCustomerId = "23df2d94c58ab"
]%%
<p>Your customer ID is %%=Uppercase(@externalCustomerId)=%%</p>
```

The example returns the string in all capital letters.

```
Your customer ID is 23DF2D94C58AB
```