---
schema_version: "1"
id: 8633769f4411f1e563f9f0c44123fb77e3d75dbe20441fb67a17158a3ad58d62
title: Customer Key
collection: admin
version: current
locale: en-us
portal_url: https://docs.salesforce.com/admin/current/en-us/mktg/264-0-0/mc_ceb_customer_key.md
canonical_url: https://help.salesforce.com/s/articleView?id=mktg.mc_ceb_customer_key.htm&release=264.0.0&type=5
source_site: help.salesforce.com
content_type: documentation
content_hash: 3911bd7d2bcce6b21d081cd33ae49ee5f0a39ab879ddbf1a74ec27019520d011
description: Each Content Builder asset has a Customer Key, a unique 36 character identifier that can be referenced via AMPscript.
products:
  - Marketing
  - Marketing Cloud Engagement
release: "264"
---
# Customer Key

Each Content Builder asset has a Customer Key, a unique 36 character identifier that can be referenced via AMPscript.

You can optionally assign your own Customer Key when creating content using any combination of letters, numbers, spaces, or special characters. If you leave the field blank, the system issues a random key.

Customer Keys must be unique across all business units in the enterprise. If you plan to reference an asset by Customer Key, use a naming convention to avoid duplicates, especially for large enterprises. For example, if you create a key of ‘logo,’ no other asset in any business unit in the enterprise can have a customer key of logo. However, if your parent business unit names an asset bu1-logo, other business units could use bu2-logo.

You can view an asset’s customer key in the list view of Content Builder, or by accessing the asset’s Properties page. Click Copy to copy it to your clipboard and include in your AMPscript references.

Use customer keys to specify a predictable identifier to your content in case the content is unintentionally moved or renamed. Referencing content by Name instead of Customer Key can result in errors. We recommend using the customer key for these references with Content Builder.