How to identify people
UpdatedIn Customer.io, people are your customers—the recipients of your messages. To add or update people in your workspace, you must identify them. Depending on your workspace settings, you can identify unique people by ID or email address.
How it works
You can identify people using values that are unique for each person, like an email address or a user id. You add and update people based on their identifiers.
To identify people, you need to first understand your workspace settings. Then you can add or update people based on the allowed identifiers:
email: A person’s email address. You may want to use this identifier to track leads before they become customers.id: A case-sensitive, unique identifier that you assign a person. Generally, this value represents a person in your backend systems, like a user ID of someone who has an account with you.cio_id: A unique, immutable identifier that Customer.io generates when you identify a person. When you identify a person bycio_id, you can update that person’s other identifiers.
Typically, you’ll programmatically add or update people through one or more integrations; this way your systems stay in sync and you know your automated messaging is sending to the right people.
Sometimes it’s useful to make one-off updates or use campaign actions to update people though. Here’s how you can identify and modify people in our UI:
| Method | Use Case |
|---|---|
| People page | Manually add or update customers. |
| CSV import | Import a file of people. |
| Create or update person action | Create or update a person from the data available in a campaign. |
Case sensitivity of identifiers
id values are case sensitive; email addresses are not. Learn more about how this influences the way we identify duplicate people below.
You should also review our info on case sensitivity across the platform. This will help you when searching your workspace, adding conditions, and adding liquid logic.
How to handle duplicate identifiers
When your workspace identifies people by email or id, we automatically merge duplicate people. Learn more in Resolve duplicate people.
id values are case sensitive, while email addresses are not. This means that id values of ab100 and AB100 represent two distinct people in your workspace.
Set allowed identifiers in Workspace settings
When you create your workspace, you set which attributes are identifiers. You can always identify people by cio_id—a unique identifier assigned by Customer.io. By default, you can also identify people by email and id. To change whether email or id are identifiers, go to your General Workspace settings.
If you’re not sure which setting is best, we recommend you leave the default setting. It doesn’t require you to add an id or email to every profile, just gives you the option to add or update your people when you identify them by email or id. It means you can store leads and existing customers so you can identify a person first by their email address and then by an id you add after they become a paying customer. If the customer ever needs to change their email address, you can do so by using their id to identify them.
Learn more about setting identifiers in Workspace settings.
Set people’s identifiers
You set identifiers when you create or update people. You must include at least one identifier, based on what your workspace settings define as identifiers.
Learn more in Add or update people.
Update people’s identifiers
If you want to update a person’s identifiers, you must first understand what your workspace settings are—if email and/or id are allowed identifiers.
This chart shows what it means to update email or id based on these settings. Note, cio_id is a permanent id our system generates for each person. It can be useful when trying to update other identifiers for a person and is typically needed when you’re programmatically updating people:
#40;where id and email are identifiers#41;"] --> f{Is it set?} f -->|yes|h{"Is #quot;cio_id
or id#quot; enabled?"} h -->|yes|j[You can set
email with id] h -->|no|i[You must update
email with cio_id] f -->|no|g[You can update
email with id] a["Update id
#40;where email and id are identifiers#41;"] --> b{Is it set?} b ---> |yes|k[You can update
id with cio_id] b ---> |no|c[You can set
id with email] n["Update id
#40;where id is the only identifier#41;"] --> o{Is it set?} o --> |yes|p{"Is #quot;cio_id
or id#quot; enabled?"} o --> |no|q[Person does
not exist] p --> |yes|r[You can update
id with cio_id] p --> |no|s[You cannot update id]
If the workspace allows identification by email and/or id (The first two charts above):
- You can change a person’s
idwhen you identify them bycio_idthrough the People page, but not CSV imports. - You can change a person’s
emailwhen you identify them byidorcio_id. Ifemailis enabled but you can only reference bycio_id, then you can only usecio_idto changeemail.
If the workspace is id-only (The third chart above):
- You can’t change
idunless you change your workspace settings. - You can update
emaillike any custom attribute.
Delete people’s identifiers
If your workspace lets you identify people by email or id, you can remove one or the other but not both. You can always identify people by cio_id; you can’t remove that identifier from a person.
If your workspace lets you identify people by id only, you cannot delete id. Whether you can change it depends on your workspace settings.
You cannot delete cio_id, no matter your workspace settings. This id is always needed for CSV imports and ensures each of your people have a unique identifier, which can help you and our support team troubleshoot issues.
