# Contact Synchronization

When logging into TelegrApp you must have in mind that only those contacts that initiate a conversation with you, will be saved in Contacts using the *senderId* (a unique identifier for Telegram users). 

If you had already contacts saved in the CRM, please note these will **not** sync as there is no index to stablish the connection with. 

{% hint style="info" %}
e.g. If you had a contact called "John Perk" in the CRM, and simultaneously were having a conversation with him through Telegram before logging in **TelegrApp** do not expect to have the contact merged.
{% endhint %}

{% hint style="warning" %}
Only after you have logged in into TelegrApp, clients that send you a message through telegram will be saved and synced (using the *senderId* index variable) in your contacts list.
{% endhint %}

In case you already had some contacts in the CRM and want to sync them with the ones in telegram, a merge will be necessary. This merge can be done in different ways:

* By hand: including the *senderId* in the specific contact's custom field will merge the contact you had prior to the TelegrApp login, with the telegram's conversation you had with the client.
* By bulk merge: the CRM allows a batch import merge option (in a specific format) of contacts, where we include variables like

  * Name & Surname (optional values)
  * Phone Number (optional / not visible for privacy)
  * Username (optional)
  * *senderId* (**imposed** by telegram)

  that the CRM will compare with the current contact database you have, assigning as an index element (name, phone, etc) one of the former variables. 

{% hint style="danger" %}
WARNING: this is **critical** as the former variables except from the *senderId* are optional, and may not be the same ones you saved in your contact database. In case you are not fully aware of these merge details, we do not recommend making a bulk merge.
{% endhint %}

If you want to continue with the **bulk merge**, we will provide a formatted document with all the available info we have to ease your synchronization efforts. This will be available in the TelegrApp Connect page, in the form of a button called "Retrieve Telegram Contact Info".

{% hint style="danger" %}
WARNING: we are not responsible for losing, deleting or modifying accidentaly any contact. The merge action is solely and purely responsibility of the user.
{% endhint %}