Compliant SMS that actually gets delivered

SMS marketing in the EU sits under two overlapping rules: the ePrivacy Directive, which demands prior consent for marketing messages, and the GDPR, which defines what that consent must look like. Get the foundation wrong and two things happen: carriers filter your traffic, and you carry real legal exposure. We get it right once, then keep it right.

Consent done to the letter

Under GDPR Article 4(11) consent must be freely given, specific, informed, and unambiguous, with a clear affirmative action. Article 7 adds that you must be able to demonstrate it and that withdrawal is as easy as giving it. We build opt-in capture that records how and when consent was obtained, because the EDPB is explicit that a correctly configured form alone is not proof.

Sender IDs, registered where it counts

An alphanumeric sender ID shows your brand name instead of a number, but acceptance is country-specific. Twilio notes 53 countries require registration. Concrete examples we handle:

Opt-out and deliverability hygiene

• STOP and HELP keywords configured, with withdrawn contacts suppressed across all sends.
• Quiet-hours and holiday rules applied per market (France's are the strictest).
• Opt-out rate watched against Klaviyo's bands, where under 0.5% is "great" and 2% is "critical".
• Branded short links and clean message construction to reduce carrier filtering.

Expanding to the US later?

US texting runs on a different system: A2P 10DLC registration through The Campaign Registry, with brand and campaign vetting plus per-message carrier fees. We cover the detail in our guide to what A2P 10DLC is, and handle the registration when you cross the Atlantic.

For the consent mechanics specifically, see our GDPR and SMS consent guide.