Two-factor authentication (2FA) gives you confidence that the number your customer provides you with belongs to them. If you are sending SMS to customers in the US, you can use a short code for this. A customer verifies their number by responding directly to the short code or via your web application. Nexmo's Two-Factor Authentication API provides this capability.
These instructions assume that you are using a shared short code. Nexmo also offers dedicated short codes specific to your organization. Find out more about short codes here.
To configure a shared US short code for 2FA:
- Sign in to the developer dashboard.
- In the left-hand navigation menu, click Numbers then Buy numbers.
- Click the add a shared short code link.
- Click the Add a short code for two factor authentication button.
- Configure your message and company name.
- Click Update. Nexmo will process your application. Approval can take up to five business days.
When you use a preapproved US short code from Nexmo, you MUST display the following information on your site's opt-in page:
- Frequency: How often users of your service can expect to receive messages from you
- How to opt out: Send a
STOPSMS to your short code.
- How to get help: Send a
HELPSMS to your short code.
- The cost to your users to receive your messages (message and data rate)
- The terms and conditions for your service