Substring()

Returns a portion of a string, beginning at a specified character position. You can optionally specify the length of the substring to return.

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

1Substring(sourceString,
2          startPosition,
3          substringLength)

The Substring() function has three parameters:

• sourceString (string): Required. The string that contains the substring you want to identify.
• startPosition (number): Required. The character position to begin the substring. If the specified character position exceeds the length of sourceString, the function returns an empty string.
• substringLength (number): The number of characters to return after the initial character. If you don’t specify a length, the substring continues to the end of the string.

This example uses the Substring() function to remove part of a string of text and return the result.

1%%[
2  Var @rewardsSegment, @rewardsTier
3  Set @rewardsSegment = "0312F-Gold"
4  Set @rewardsTier = Substring(@rewardsSegment, 7)
5]%%
6<p>Thank you for being a %%=v(@rewardsTier)=%% rewards member!</p>

The example returns the specified substring.

1Thank you for being a Gold rewards member!