---
title: "The CampaignId method"
slug: "the-campaignid-method"
abstract: "Overview of the CampaignId method and properties."
---
# The CampaignId method

To define the campaign ID for an interaction, use the `CampaignId()` method.

| Property | Details |
| --- | --- |
| UT SDK method | `CampaignId(string)` |
| Required/optional | Optional |
| Multiple invocations | Multiple invocations are forbidden and cause an *InvalidOperationException* exception |
| Value validation | Must contain a proper item ID value |