Acceptable use

Allowed

• Your own sign-ups: verifying accounts you use yourself
• Privacy: when you would rather not share your personal phone number
• Services in other countries: when a local number is required
• Development and testing: checking SMS verification in your own app

Prohibited

• Using someone else's identity or impersonating a person or organization
• Creating accounts for fraud, phishing, spam or anything that deceives or harms others
• Reselling received codes or verifying accounts on behalf of others
• Mass-creating accounts with software to abuse a service

If the rules are broken

Accounts used for prohibited purposes may be suspended without notice, and the remaining balance may not be refunded.

Refund and cancellation rules are in the terms.