# Enable two-step authentication using text messaging (SMS)

### To enable two-step authentication using text messaging (SMS), go to your user profile and click "Add" under the two-step authentication section, then select "Add SMS". Add your phone number and confirm it with the unique verification code sent to you. Store the backup code provided in a safe place, and Stripe will request a code for new devices and periodically for security.
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Before you enable two-step authentication using text messaging, please note that SMS is **unencrypted**, requires cell reception, and is **vulnerable** to SIM swap attacks. Once your phone number is known, there is currently no feasible way to defend yourself from SIM swap attacks. Stripe encourages you to use [an authenticator app](/questions/enable-two-step-authentication-using-a-mobile-app) or a hardware security key instead.
If you would like to use SMS anyway:
1. Go to your [user profile](https://dashboard.stripe.com/settings/user).
1. Click **Add** under the **Two-step authentication** section.
1. Select **Add SMS**. You will be asked to enter your phone number. Enter your phone number and click **Confirm phone number**. 
1. You will be sent a unique verification code to confirm that we've got the right phone number. Note that it may take a minute or two to receive your verification code.
1. Write down the [backup code](/questions/backup-codes-for-two-step-authentication-requirement) shown and store it in a safe place.
The setup process is then complete. Going forward, Stripe will request a code if you sign in from a new device, as well as periodically to make sure it's still secure.