Last updated:
09.03.2026
Opt-in (newsletter registration)
An opt-in is a user's explicit consent to receive marketing messages. In WhatsApp marketing, opt-in is the legal prerequisite for every message – no consent, no contact.
hellomateo offers ready-made opt-in flows: QR codes, landing pages, and click-to-WhatsApp links guide interested parties through a simple registration process – GDPR-compliant and automatically documented.
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Opt-in describes the active step by which a user declares their consent to receive marketing messages. Unlike opt-out, consent must be given explicitly and voluntarily.
Single Opt-in vs. Double Opt-in
Single Opt-in: one-time registration. Double opt-in: Confirmation in a second step – maximum legal certainty and higher list quality. Opt-in methods for WhatsApp: QR code: Scanning leads directly to an opt-in flow. Landing page: Form with phone number and consent text. Click-to-WhatsApp: Clicking on the ad opens a WhatsApp chat. Keyword opt-in: Customer sends START to a number. Opt-in management with hellomateo: Registration processes are automatically documented, double opt-in is managed, and opt-outs are processed immediately. All consents are stored in an audit-proof manner.