Consent determines who you can message, and it must apply across every channel you send on. Insider One stores consent on the customer profile. An opt-out collected on one surface applies to sends on every other surface in the same account.
This article explains where consent lives, how an opt-out is enforced, and which records you can produce when someone asks you to prove it. If you are setting up a channel for the first time, start with the opt-in guide for that channel, linked below.
This article covers:
Where consent is stored
Consent is a profile attribute in the Unified Customer Database, alongside the rest of a customer's attributes and events. Every surface that collects consent writes to the same profile, whether the change arrives from a preference center, a campaign, or an API call.
Collect opt-ins through the guide for each channel:
For email, you can require double opt-in so a subscription counts only after the customer confirms it. See Introduction to Email Double Opt-in.
How customers opt out
Customers reach the Global Unsubscribe & Preference Center from a link in your messages. From there, they can stop all commercial email in one action, or choose which categories to keep. For setup, see Global Unsubscribe & Preference Center.
Email also supports the one-click List-Unsubscribe header, which Gmail and Yahoo require for bulk senders. The header lets a customer unsubscribe from the mailbox interface without opening your message. See One-Click List-Unsubscribe Header.
Each channel keeps its own global unsubscribe list as well:
How suppression is enforced at send time
An opt-out updates the customer profile, and the profile is read when the campaign builds its recipient list. Nothing waits for a batch job, so a customer who unsubscribes is excluded from the next send.
You can also target or exclude recipients by unsubscribe group. That is how a service-style email keeps reaching someone who has opted out of promotional content. See Standard Segments: Unsubscribe Groups and Unsubscription Management.
Email adds Central Bounce suppression, which holds back sends to addresses that have hard bounced. Configure it in Settings > Email Settings, described in Email Settings.
Opt-in attributes do not override global unsubscribe
An opt-in attribute records a user’s permission for a channel. It does not, by itself, confirm that the user is reachable. A user can have email_optin set to true and still be unreachable because the email address remains globally unsubscribed or has another blocking status. Updating an opt-in attribute is not a substitute for the channel’s resubscribe operation.
For SMS, the Global Unsubscribe list contains phone numbers and prevents future SMS messages from being sent to those numbers. Do not rely on a profile’s sms_optin value alone to determine whether a globally unsubscribed number can receive messages.
If a user gives permission to receive messages again, use the relevant channel’s Resubscribe API. For SMS, you can also remove the contact through Audience > Suppression > Global Unsubscribe > SMS. Only resubscribe users who have opted back in.
After resubscribing, verify the change in Global Unsubscribe and check the user profile. A successful API response confirms that the request was queued, not that the change has already been applied.
For email, resubscribing does not clear the system-managed spam status.
Transactional and promotional messages
A transactional message confirms something the customer did, such as an order or a password reset. A promotional message markets to them. The distinction matters because consent requirements differ, and in some markets so does the registration you need.
For SMS, you register transactional and promotional senders separately, and the sender type you use determines which consent rules apply. See Transactional SMS Setup and Sender Submission.
In Türkiye, commercial electronic messages must be reconciled with the İleti Yönetim Sistemi (İYS). See İYS Integration and SMS Subscribers.
Audit and data subject requests
Consent changes appear on the customer's profile with the time they happened, described in Elements of a User Profile.
For access and deletion requests, Insider One exposes REST APIs including Delete PII and Delete Profile. See Insider One's Commitment to End Users' Rights.
What to do next
Consent lives on the customer profile, opt-outs apply at send time, and each channel keeps a global unsubscribe list you can import into. Set up the preference center before your first promotional send. Retrofitting consent records after a campaign is far harder than collecting them correctly.