OTP (One-Time Password)

A one-time password (OTP) is a temporary, automatically generated code sent to a user via email or SMS that is valid for a single authentication session. Unlike static passwords, an OTP expires after a short window — typically a few minutes — and cannot be reused. In digital publishing, OTPs serve as a verification mechanism to confirm that a reader actually owns the email address they provided before granting access to [gated content](/glossary/gated-content). This prevents fake submissions and ensures that every captured contact is a real, reachable person.

Without email verification, lead capture forms are vulnerable to junk submissions. Readers may enter misspelled addresses, disposable emails, or entirely fabricated contacts, degrading the quality of your lead database over time. OTP verification solves this by requiring proof of email ownership before content access is granted. The result is a cleaner, more reliable contact list where every address has been confirmed as valid and deliverable. For publishers distributing confidential or premium content, OTPs also act as an access control layer, ensuring that only verified recipients can view sensitive material and that forwarded links cannot be used without re-verification.

FlipLink supports OTP verification as part of its [lead capture](/features/lead-capture) and [privacy and access control](/features/privacy-and-access-control) features. When a publisher enables OTP on a lead capture form, the reader enters their email address and receives a six-digit verification code at that address. The reader then enters the code to confirm their identity, and only after successful verification is the publication content unlocked. This works alongside [email allowlisting](/glossary/email-allowlist) for layered access control — you can restrict which email domains are allowed and then verify each individual address with OTP. The entire process takes seconds for the reader while dramatically improving the quality of captured lead data.