Overview
With Customer.io, send targeted emails, push notifications, and SMS to lower churn, create stronger relationships, and drive subscriptions.
How does it work?
User clicks on a link in an email from their mobile mail client (Gmail, Apple Mail, etc.)
If the user has the app installed and the link has a corresponding screen in the app, the app will open and deep link the user to the right content if the link was designated to open the app.
Ex. Product detail page, category shopping page, etc.
If the user does not have the app installed or the link only corresponds to a screen on the web, the user is routed to the website using their default mobile web browser.
Ex. Unsubscribe link, privacy policy, etc.
Prerequisites
Required Roles
Branch's Branch Email requires the following roles involved in order to enable:
Developers
CRM/Email Team
Customer.io Account Manager / Support Team
In order to enable Customer.io, you need to have completed the following:
Admin access to your Branch Dashboard.
Have Branch's Engagement product enabled for your Branch Account.
Implemented the Branch SDK into your mobile app (iOS | Android)
Set Up Deep Link Routing. How your mobile app routes to in-app content will determine how you will create and tag your Branch Links.
Obtained or set up your Customer.io click tracking domain (CTD). Reach out to your Customer.io account manager for assistance on this.
Enable Customer.io
Connect Customer.io Service in Branch
In the Branch Dashboard in Email → Manager tab, find Customer.io and click Enable
Input Click Tracking Domain
Click tracking domains allow you to track engagement on email opens and link clicks.
The Customer.io integration requires you provide the following:
Click Tracking Domain - The domain you use with Customer.io for links in emails
Click Tracking Domain
Remove
https://when adding your click tracking domain.Never add the same CTD to both your Live and Test Branch environments.
You can enable the integration with multiple CTDs, if needed, but you cannot add the same CTD to multiple Branch Dashboards or ESP integrations.
Configure your App
Add your Customer.io CTD to your Associated Domains
For your iOS App, you must add the CTD to the Associated Domains. Additional details can be found here.
.png?sv=2022-11-02&spr=https&st=2025-07-11T08%3A24%3A23Z&se=2025-07-11T08%3A37%3A23Z&sr=c&sp=r&sig=3Ob4XbTisN7SH6w4LDCBlzynarOzurWUvv8ECgkgx%2Fc%3D "Associated Domains.png")
Return YES to continueUserActivity
Additionally, you will need to add the CTD to your iOS app's info.plist file. Additional details can be found here.
.png?sv=2022-11-02&spr=https&st=2025-07-11T08%3A24%3A23Z&se=2025-07-11T08%3A37%3A23Z&sr=c&sp=r&sig=3Ob4XbTisN7SH6w4LDCBlzynarOzurWUvv8ECgkgx%2Fc%3D "branch-universal-link-domain.png")
Point DNS CNAME to Branch
Please follow your web hosting provider’s instructions on how to configure your DNS CNAME.
Update the DNS CNAME and point it to thirdparty.bnc.lt. Once the CNAME record is added, please allow up to an hour for Branch to generate SSL and AASA files for your click tracking domain.
Important CNAME Info
The Branch dashboard must be enabled & reflect the CTD BEFORE you add the CNAME.
If the CTD already has SSL setup, confirm if your security credentials allow a 3rd party to submit a CSR on behalf of the domain. If not, contact Branch's Support team, to coordinate providing an SSL certificate manually to Branch.
Once the CNAME is added, Branch auto-generates an SSL certificate and AASA file for your click tracking domain. It may take up to an hour to resolve SSL errors once you change the CNAME. During this time, link redirects on the click tracking domain will redirect to the Default URL you provided in the General Configuration section of your account.
If you are making this change to a live domain with active email click traffic, schedule the CNAME change to occur during an off-hours time with low click traffic.
Add Branch Links to your Emails
Before you start sending your email campaigns, you need to determine what flow you want the user to experience and flag your email links accordingly. By default, your links will open web. In order to open the app, you will need to add the deep linking flag.
Add Deep Linking Flag
For the email links that you would like to deep link to content, add $deep_link=true to the URL as a query parameter, for example:
<a href="links.example.com?$deep_link=true" >Link to your app!</a>This will ensure that your links are converted to Branch links that will open the app on iOS and Android, with full tracking and attribution.
Analytics on the Branch Dashboard
To see how the email campaigns have performed and break it down into campaigns, it is very essential to tag your email links with the ~campaign tag. If your team uses UTM tags, Branch will also ingest the UTM_campaign tag. This will help dedupe the numbers and hence see the downstream events. You can add the campaign tag in any comparisons and filters in any Dashboard views.