SMS Opt-Out Everything You Need to Know

SMS Opt-Out Everything You Need to Know

At LINK Mobility, we often hear from mobile users who feel their SMS opt-out request has not been respected. In reality, most brands using our platform follow all required guidelines. The confusion usually comes from not understanding how SMS opt-out works - and who is responsible for processing it.

In this blog, we explain what SMS opt-out means, how to implement it correctly, and why it is essential for both regulatory compliance and customer trust.

What SMS Opt-Out Means

SMS opt-out is the process that allows users to unsubscribe from marketing or informational text messages by replying with a keyword - usually “STOP”. This keyword must be recognized and processed immediately by the sender to prevent future messages to the same mobile number.

An effective SMS opt-out process should be:

  • Free to the user

  • Available in every message

  • Simple to execute

  • Compliant with national and international regulations

SMS Opt-Out and GDPR Compliance

In the European Union and many other regions, SMS marketing falls under personal data regulations such as the General Data Protection Regulation (GDPR). These rules give individuals the right to control how their personal information is used - including the right to withdraw consent at any time via SMS opt-out.

Core GDPR requirements for SMS

  • Explicit consent is required before sending promotional SMS.

  • Clear purpose disclosure must be given at the time of data collection.

  • SMS opt-out instructions must be present in every message.

  • User data must be deleted or anonymized when no longer necessary.

  • Brands must document opt-ins and opt-outs to demonstrate compliance.

Failing to meet these conditions can result in fines, filtering of your campaigns by mobile operators, or long-term damage to your sender reputation.

Local Variations in SMS Opt-Out Rules

While GDPR sets the baseline across Europe, many countries have added national rules or industry-specific guidance.

Below is an overview of SMS opt-out requirements in LINK Mobility’s key markets:

CountrySMS Opt-Out Rule
FranceNo SMS allowed between 8 PM and 8 AM, or on Sundays/holidays. “STOP to 36200” is required.
GermanyRequires double opt-in for marketing. Opt-outs must be processed promptly and logged.
United KingdomA clear “STOP” instruction is mandatory in every message. Enforced by the ICO.
United StatesOpt-outs must be honored immediately. Brands must keep opt-in and opt-out logs (TCPA).
ItalyOpt-out instructions must be present in all SMS. Enforced by the Garante Privacy Authority.
SpainSMS must follow GDPR and LSSI rules. Users must be able to opt out in every message.
SwedenMarketing SMS must include opt-out details. Violations can be reported to IMY.
NorwaySMS marketing requires prior consent. “STOP” must be free and effective.
DenmarkCompanies must document consent and include SMS opt-out in each message.
FinlandOpt-out must be offered in all marketing SMS. Regulated by Traficom.

Each brand is responsible for understanding and following the local rules where they send messages.

Common Misunderstandings About SMS Opt-Out

One of the most frequent issues we see is a misunderstanding of how opt-out applies:

Replying “STOP” only opts you out from the brand that sent the message - not all SMS you receive.

If multiple brands use LINK Mobility’s messaging infrastructure, each one is still an independent sender. SMS opt-out only applies to the sender whose message you replied to.

For example:

  • You receive a campaign SMS from Brand A.

  • You reply “STOP.”

  • You are unsubscribed from Brand A - but not from Brand B, even if they also use LINK Mobility.

This ensures user control remains brand-specific.

Best Practices for SMS Opt-Out

To comply with regulation and protect your brand reputation, it is important to follow these global best practices:

  • 1. Include SMS Opt-Out Instructions in Every Message

    Always add a short, clear line like: “Reply STOP to unsubscribe.”

  • 2. Process Opt-Outs Immediately

    There should be no delay in unsubscribing a user once their STOP message is received.

  • 3. Store Opt-In and Opt-Out Logs

    Keep secure records of when and how users opted in and out to protect your brand in case of audits.

  • 4. Adjust for Local Rules and Short Codes

    Some countries, like France, require a specific opt-out code and format. Be sure your campaigns follow local telecom rules.

  • 5. Automate Data Removal

    Once a user opts out, remove or exclude their number from future sends - automatically and reliably.

Identifying the Sender of an SMS

To make the opt-out process meaningful, recipients need to know who they are opting out from. Ensure your messages include:

  • A recognizable brand name or sender ID

  • A clear explanation of why the message was sent

  • A SMS opt-out instruction tailored to that sender

This helps reduce confusion and prevents complaints to operators or regulators.

Why SMS Opt-Out Builds Customer Trust

Beyond compliance, giving users control over how they hear from you is key to long-term success. A reliable SMS opt-out process shows that you respect personal preferences and privacy rights.

When users trust that they can opt out easily, they are more willing to opt in.

It also helps reduce spam complaints, improves sender reputation, and increases deliverability of future campaigns.

SMS Opt-Out as a Standard in Responsible Messaging

At LINK Mobility, we treat SMS opt-out as a critical part of every messaging strategy.

Our systems are designed to support:

  • Real-time opt-out handling

  • Localization of opt-out formats

  • Secure logging and reporting

  • Compliance with GDPR and other global regulations

Did you find the article and topic interesting?

If you would like to explore the subject further, discuss ideas, or understand how it could apply to your business, we are here to continue the conversation.

LINK Mobility Group
Office: Gullhaug Torg 5, 0484 OSLO
Postal: Postboks 4605 Nydalen, 0405 OSLO
Email: info@linkmobility.com
Tel: +47 22 99 44 00

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