How to set up two-factor authorization in a Telegram bot

What is a 2FA in a Telegram bot

Two-factor authorization (2FA) is an additional check at login/important actions: a second factor is added to the Telegram password/session (one-time code, biometrics, confirmation in the application, passkey). In the context of the bot, 2FA is configured on the service side, and the bot acts as an interface: it helps to enable 2FA, issues instructions, accepts codes, launches WebApp for confirmations.

Key scenarios where 2FA is mandatory:

login to personal account (via bot → WebApp → profile), linking/changing payment methods, withdrawal requests, changing e-mail/phone, password/limits, login from a new device/from a new country.

2FA options available in bot

1. TOTP (authenticator application) - Google/Microsoft Authenticator, 1Password, Bitwarden, etc. Generate 6-digit codes every 30 seconds (RFC 6238).

2. Reserve codes - a set of one-time static codes for a "rainy day." Keep offline.

3. Confirmation in WebApp - the bot opens Telegram WebApp, where you confirm the action (step-up).

4. The code in e-mail/SMS is a backup option when there is no access to TOTP.

5. Passkeys/WebAuthn (if supported by the service) - login/confirmation without a password via device biometrics (Face/Touch ID), as a second factor or instead of a password.

💡 Important: 2FA in the bot ≠ the Telegram password. The Telegram (Cloud Password) password is protected by the Telegram account itself; it should also be enabled, but this is a separate setting in the Telegram client.

How to enable 2FA in a bot (step by step)

Step 1. Open the security section

In the bot, select Menu → Profile/Security → Two-factor authentication or send the command/security → Enable 2FA.

Step 2. Choose a method

TOTP (reliable and autonomous) is recommended. If not, connect e-mail/SMS as a backup.

Step 3. Connect TOTP

1. The bot will show a QR code (or a secret key in the format 'otpauth ://'/base32).

2. Open the authenticator application → Add → Scan QR (or Enter key).

3. Enter the current 6-digit code from the authenticator in the bot to confirm.

4. Save the reserve codes (the bot will give 8-10 codes). Download/record offline.

Step 4. Check the backup channel

Make sure that the e-mail is confirmed, the phone is up to date: this will help with the loss of TOTP.

Step 5. Enable step-up on critical operations

In the 2FA Settings section, mark: "Request 2FA when displaying/changing details/limits."

Step 6. Test

Log out of the session → log back in via the/WebApp bot - the system will ask for the 2FA code.

How it works "under the hood" (short)

The bot/web account determines your identity through Telegram Login (signed data from Telegram) or your authorized 'telegram _ id'.

The server side stores the TOTP secret (base32) associated with your account (encrypted).

For an operation requiring 2FA, the server waits for a 6-digit TOTP code (or confirmation via WebApp/Passkey).

The server checks the code against the current time window (typically 30 seconds) against the time drift tolerance.

On success, the operation is performed; in case of failure - lock/captcha/timeout/risk notification.

Security Best Practices (User)

Connect TOTP + protection codes. Don't keep them in notes/gallery - print them out.

Enable step-up for cash/output/change of details.

Do not send codes to "managers" in your personal account - enter only in the official bot/WebApp.

Make sure that you have the Telegram (Cloud Password) password and Telegram blocking by code/biometrics enabled.

If you lose your phone - right away: change your account password, disconnect old devices, use backup codes, contact support.

Best Practices (for admins/product)

Storage of TOTP secret: in KMS/in encrypted field (AES-GCM), with separation of access roles.

Rate limiting and brute force protection: Limit code attempts, add exponential delays and captcha.

Time window: 30 sec + tolerance ± 1 window; consider clock drift.

Step-up: require 2FA to output, change payment methods, KYC data, when logging in from a new device/country/suspicious IP.

Sessions: show the user active devices, let's click the "Exit from everywhere" button.

Audit: log 2FA confirmations (without storing the codes themselves), slap alerts in case of anomalies.

WebApp: validate 'initData '/Telegram signature on the server; expiring'auth _ date '; protect against replay (nonce).

Passkeys: add WebAuthn support (as a second factor or passwordless), store device binding keys.

Reserve codes: issue once, give regeneration with identity confirmation.

UX: clear error states, timers, a counter of remaining attempts, an understandable "ladder" of access recovery.

Common mistakes and how to solve them

The code is incorrect: check the time on the device with the authenticator (enable auto-synchronization of time), wait for the next 30-second window.

No access to TOTP and backup codes: use a confirmed e-mail/phone, go through the recovery procedure (KYC-identity confirmation).

No e-mail/SMS arrives: check spam, phone correctness, repeat in 60-120 seconds; for system delay, use TOTP.

WebApp asks for re-login: 'auth _ date' has expired or session has been reset; re-enter via the button in the bot.

Too many attempts: wait for timeout, then try again; in case of frequent failures, change the TOTP secret and reassign the authenticator.

Mini checklist before turning on 2FA

1. Authenticator installed, auto-time enabled.

2. Confirmed e-mail and phone (backup access).

3. TOTP secret added via QR/key, first code verified.

4. Backup codes are kept offline.

5. Step-up is enabled for cash/output/change of details.

6. The Telegram (Cloud Password) password and client lock are enabled.

FAQ

Does 2FA in the bot replace the password?

No, it isn't. This is an additional check. You still need a password/main login.

Can I turn on 2FA for output only?

Yes, through security settings (step-up for critical operations).

Which is more reliable: TOTP or SMS?

TOTP is more reliable: it does not depend on the network, it is not vulnerable to SIM swaps. SMS/e-mail is a fallback.

Passkeys work in Telegram WebApp?

If the service supports WebAuthn in the built-in client browser and your platform allows it, yes. Otherwise, use TOTP.

I changed my phone. Need to be reconfigured?

Yes I did. Migrate the authenticator account (export) or reset the secret and configure TOTP again. Backup codes will help you enter the transition period.

2FA in the Telegram bot is an easy way to significantly increase security: TOTP + backup codes + step-up for sensitive operations. Connect an authenticator, save backup codes, enable confirmations for the cash register and payment changes - and your account will remain protected even if the password or device is compromised.