> For the complete documentation index, see [llms.txt](https://docs.b2core.b2broker.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.b2core.b2broker.com/troubleshooting/email-and-notification-issues/clients-not-receiving-2fa-codes.md).

# Clients not receiving 2FA codes

## Problem

A client has enabled either **Google Authenticator** or **SMS confirmation** in the **Security** section of the B2CORE UI, but can't receive 2FA codes.

## Possible reasons

**Google Authenticator**:

* The client has lost access to the app or the device on which it was installed.
* The app isn't generating valid codes due to incorrect time synchronization on the device.

**SMS confirmation**:

* The SMS provider configuration in the Back Office is incomplete or incorrect.
* Your SMS provider account doesn't have sufficient balance.
* The SMS provider service is temporarily unavailable.
* The client’s mobile operator blocks or delays SMS messages.

## Solution

To fix 2FA issues:

{% stepper %}
{% step %}

#### Verify client 2FA settings

* In the Back Office, navigate to **Clients** > **General**.
* Find the client in the list and click the **Edit** button.
* In the client details, go to the **Settings** tab.
* In the **2FA** section, check whether one of the 2FA options is enabled for the client. If not, the client must enable 2FA in the **Security** section in the B2CORE UI.

<figure><img src="/files/hPoY4b70d7axbva2KJSJ" alt="2FA section in client details"><figcaption><p>2FA section in client details</p></figcaption></figure>
{% endstep %}

{% step %}

#### Troubleshoot Google Authenticator

If the client can't generate valid codes or has lost access to the app or device:

* You may disable the option on the **Settings** tab in the client details in the Back Office.
* Ask the client to re-enable the Google Authenticator 2FA in the **Security** section in the B2CORE UI.

{% hint style="warning" %}
Disabling 2FA removes an additional layer of protection. This action should only be performed at the explicit request of the client and under their sole responsibility.
{% endhint %}
{% endstep %}

{% step %}

#### Troubleshoot SMS confirmation

* In the Back Office, navigate to **System** > **SMS providers**.
* In the provider list, click the **Edit** button for the related provider, such as **Twilio**, to open its configuration details.
* In the the **Provider settings** section:
  * Verify that the credentials are correct.
  * Ensure that the configuration is enabled.
  * Confirm that your SMS provider account has a sufficient balance for message delivery.

<figure><img src="/files/FnEFjWUGa34kaksF4cxW" alt="Twilio provider settings"><figcaption><p>Twilio provider settings</p></figcaption></figure>

If the configuration is correct but issues persist, contact the SMS provider to check for service disruptions or delivery issues with the client’s number.
{% endstep %}
{% endstepper %}


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