Register Contacts and Devices

To register contacts and devices with Marketing Cloud Engagement, work with your marketing team to determine your contact key strategy, configure attributes and tags, and set all required registration fields.

Before you begin, configure the SDK and initialize it. See Use the SDK with Marketing Cloud Engagement.

The contact key is a unique identifier that represents an individual in Marketing Cloud. Your contact key strategy influences how you implement registration and determines whether you can send messages to anonymous users, known users, or both.

• Determine Your Contact Key Strategy — Understand contact key options and their implications for messaging
• Set the Contact Key — Configure the contact key in your app using the SDK

Use attributes and tags to segment your audience and personalize messages. Attributes are key-value pairs for demographic data, while tags are categories that let users express interests or preferences.

• Set Contact Attributes and Tags — Overview of attributes and tags, including how to create custom attributes and manage both
• Set or Clear Attributes — Manage attribute key-value pairs using the SDK
• Manage Tags — Add or remove tags using the SDK

When a user changes their contact key or multiple users share a device, contacts can become dissociated from devices. Understanding and managing this behavior helps maintain accurate contact records.

• Contact Dissociation — Understand why contacts become dissociated and how to minimize it
• Delay Registrations Until Contact Key is Set (Android) — Configure Android apps to delay registration
• Delay Registrations Until Contact Key is Set (iOS) — Configure iOS apps to delay registration

After implementing registration, verify that all required fields are properly set and that Marketing Cloud successfully processes the registration.

• Check Required Registration Fields — Understand required fields and validate registration data