# Embedding IDs in Links

Source: https://docs.ezoic.com/docs/identity/embedding-ids-in-links/


You can include a user id, email hash, or phone number hash in any URL parameter and Ezoic will automatically read it and provide the identity information to advertising providers. The **value prefix** determines what type of identity is being passed — email or phone.


We recommend using a UTM parameter, though ***any*** parameter will work. The parameter name does not matter — only the value prefix.


## Email Identity

| Field | Prefix | Example |
|-------|--------|---------|
| User ID | `zid` | www.publisher-website.com/mypage?utm_content=zid-123 |
| MD5 | `zmd5` | www.publisher-website.com/mypage?utm_source=zmd5-1a2b3c |
| SHA256 | `zsha256` | www.publisher-website.com/mypage?utm_myparam=zsha256-1a2b3c |
| SHA1 | `zsha1` | www.publisher-website.com/mypage?myparam=zsha1-1a2b3c |


Providing the user ID will often be the most effective way to pass identity data but will only be available if you have completed an email service integration.



You can include multiple hashed emails in the URL. SHA256 is recommended, but you can pass any combination of the three hashes.


## Phone Number Identity

| Field | Prefix | Example |
|-------|--------|---------|
| SHA256 | `zphonesha256` | www.publisher-website.com/mypage?utm_phone=zphonesha256-1a2b3c |


`zsha256` is for **email** hashes only. For phone number hashes, use `zphonesha256`. Using `zsha256` with a phone hash will cause it to be treated as an email hash.



Phone numbers should be normalized to [E.164](https://en.wikipedia.org/wiki/E.164) format before hashing. See the [Getting Started](/docs/identity/getting-started/#phone-number-hashed-or-unhashed) page for normalization details.


## Passing Both Email and Phone

You can pass both email and phone identity in the same URL using separate parameters:

```
www.publisher-website.com/mypage?utm_email=zsha256-<email_hash>&utm_phone=zphonesha256-<phone_hash>
```