Definition
A legitimate interest assessment is a three-part test that organisations must complete and document to rely on legitimate interest as their legal basis for sending marketing emails. It is most commonly used for B2B email marketing where consent is impractical.
The Three-Part Test
- Purpose test: What is the legitimate interest? (e.g., promoting relevant business services to professionals in your sector)
- Necessity test: Is the processing necessary? Could you achieve the same result with less intrusive means?
- Balancing test: Does the individual's rights and interests override your legitimate interest?
Why It Matters
Without a documented LIA, you cannot legally rely on legitimate interest as a basis for sending. If a B2B recipient complains to their data protection authority, you must be able to produce your LIA as evidence. Regular review and updates are recommended as business practices evolve.
Best Practices
- Start with the fundamentals of Legitimate Interest Assessment (LIA) and build from a clear baseline, so later improvements are measurable rather than assumed.
- Keep Legitimate Interest Assessment (LIA) consistent with how the rest of your email programme works, so no single initiative works against another.
- Review how Legitimate Interest Assessment (LIA) is handled in your own data and adjust from what you see, rather than copying what another brand does.
- Test one change at a time and measure the effect before rolling it out more widely.
- Revisit your approach to Legitimate Interest Assessment (LIA) regularly, because audience behaviour and inbox technology keep moving.
- Make sure the basics — relevance, timing, and honesty — are solid before chasing more advanced tactics.
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Related Glossary Terms
Abuse Complaint
An abuse complaint is a report from a recipient who marks an email as spam, which negatively affects sender reputation and deliverability.
Account-Based Marketing Email
An account-based marketing email is a highly targeted message sent to a specific organisation or decision-maker group as part of a focused B2B strategy.
Anonymized Data
Anonymized data is email subscriber or interaction data that has been stripped of personally identifiable information so individuals cannot be re-identified.
Australia Spam Act 2003
The Australian Spam Act 2003 bans unsolicited commercial email, requiring consent, accurate sender information and a clear, working unsubscribe facility on every message.
Brazil LGPD Email Marketing
Brazil's LGPD regulates personal data use for marketing, requiring a legal basis such as consent or legitimate interest, plus transparency and clear opt-out in email campaigns.
CAN-SPAM Act
The CAN-SPAM Act is a US law that sets rules for commercial email. It requires accurate subject lines, a physical address, a clear opt-out mechanism, and prompt processing of unsubscribes. Violations can result in penalties up to $51,744 per email.
Frequently Asked Questions
Good practice here means handling Legitimate Interest Assessment (LIA) in a way that is relevant, timely, and honest for your audience. A legitimate interest assessment (LIA) is a documented test that proves you have a valid legal basis for sending B2B marketing emails under the GDPR without explicit consent. Done well, it improves engagement and builds trust; done poorly, it creates friction that costs you results.
Because it touches the parts of email that drive outcomes: relevance, trust, and delivery. Small improvements compound, while repeated mistakes quietly erode the health of your programme.
The most common problems are treating Legitimate Interest Assessment (LIA) as a one-off task, ignoring what the data says, and copying competitors without testing. All three lead to effort that does not translate into better results.
Compare the metrics it should influence — engagement, conversions, and deliverability — before and after you make changes. Trends over time matter far more than any single send.
It supports the same goal as the rest of your email programme: the right message to the right person at the right time. Aligned with segmentation and automation, it reinforces everything else rather than competing with it.