Nexmo Verify makes phone verification easy. You only pay for successful authentication. Deliver verification codes over the fastest routes determined by Verify in real-time. Verify automatically resends a code and failsover to voice if needed. Verify detects and blocks virtual, Premium, and Toll-Free numbers that are used for spam and fraud. PIN codes are generated using the industry standard RFC6238 algorithm – and expire within minutes. Verify ensures your messages are compliant and abstracts the complexity of monitoring global carrier and country regulations. Languages and voice accents are adapted to regional preferences to maximize verification success. Simply send Verify a phone number. Verify detects the number type and selects the appropriate channel - SMS or voice. Customize message templates, pre-record voice calls, and configure the time between retries to deliver the user experience you desire.