# Telegram Privacy Overview

When you use Telegram, not all parts of your profile are public. Some details are required by Telegram, some are optional, and some are only visible depending on your privacy settings.\
This section explains, in simple terms, **what information exists in every Telegram account, what is optional, and what our system can or cannot see.**

### Mandatory Information

These details exist on every Telegram account and cannot be turned off:

* User ID: A unique number Telegram gives to every user.\
  It does *not* reveal your phone number or identity — it's just an internal identifier used by apps to recognize your account.

* First Name: Telegram requires every user to set a first name.\
  This can be your real name, a nickname, or even an emoji — it’s simply the name that appears in chats.

### Optional Information

The following details are **not required**, and many users choose to leave them empty:

* Username: A public name like `@john_doe`. This is optional. Many people don’t set one.\
  If you don’t have a username, you can still use Telegram normally.
* Last Name: Totally optional. Most users leave it blank.
* Profile Photo: Optional. If you add one, some people may still not see it depending on your privacy settings.

### Private Information

The following details are **shared only if you allow it:**

* Phone Number: Your phone number is **not shared by default**. Apps and bots can only see your number if:
  * You choose to share it manually, or
  * You have the other person saved in your contacts **and** your privacy settings allow visibility.
* Online Status: You can choose: Everyone, Contacts Only or Nobody. If hidden apps and other users will only see "last seen recently"

### What TelegrApp Can and Cannot See

Telegrapp stores and uses Telegram's User ID to send and receive messages. This value is stored within each contacts' information inside a custom field called "SenderId". Telegrapp tries to obtain the contact's phone number and full name whenever possible since it might not be always allowed. 

Whenever a new contact talks to you via telegram, telegrapp will automatically fetch and store the User ID for future interactions under the "SenderId" field. 

If you start a conversation with a contact which has still not talk to you via Telegram, you will need to make sure that your contact has a **valid Phone Number.** In this case, Telegrapp will try to use the contact's phone number to send the first message. Afterwards, it will automatically switch to using the User ID

#### **Editing the User ID Field**

{% hint style="info" %}
**NOTE**: **You can replace the User ID with a Telegram username, but its less recommended**
{% endhint %}

Inside your CRM, you are free to edit or replace the User ID field for any contact.

Our system will still work if you enter a username like `@john_doe` instead of a numeric User ID.

**However**, this is not the most recommended way since depends on your customers' privacy settings. Always use the default User ID whenever possible. Don't worry, by default, this is already handled by TelegrApp every time you talk to any of your contacts.