What Is Cookie Consent? - Klaviyo UK
2026-03-10 21:12 Diff
https://www.klaviyo.com/uk/glossary/what-is-cookie-consent

Cookie consent is permission from website visitors to use cookies—small text files that track behaviour, remember preferences, and help deliver personalised experiences. Because cookies can collect personal data or track online behaviour, many privacy laws require businesses to get consent before using them.

For marketers, cookie consent is more than just a legal box to tick. It also helps build trust with your audience. When visitors arrive on your site, a cookie consent banner or pop-up gives them control over what data they share. This transparency helps establish a relationship based on respect and shows a clear commitment to consumer privacy.

Getting cookie consent right also shapes your marketing capabilities. Without proper consent, you can’t collect the behavioural data you need to segment your audiences, trigger marketing automations, or personalise your messaging. A well-designed cookie consent experience balances compliance with usability, making it easy for visitors to say yes while respecting their right to say no.

Why cookie consent matters

Privacy regulations have changed how businesses collect and use customer data, but not all consent is the same. Laws such as the General Data Protection Regulation (GDPR) in Europe and the California Privacy Rights Act (CPRA) in the US require organisations to clearly define why they are collecting data and how it will be used. Cookie consent specifically governs the use of cookies and similar tracking technologies, not broader permissions such as email or SMS marketing consent.

Under these regulations, businesses must categorise cookies by purpose—such as strictly necessary (functional), analytics, or marketing—and communicate those purposes clearly to users. In the EU, users must explicitly opt in to any non-essential cookies, including analytics and marketing cookies. In California, the default is different: consumers generally have the right to opt out of the “sale” or “sharing” of their data, particularly for cross-context behavioural advertising. While the mechanics vary by region, the common thread is transparency and user control.

Regulations also require organisations to define how long cookies can persist. While one year is often considered a standard for long-lived cookies, browser-level changes increasingly shape what’s actually possible. For example, Safari’s Intelligent Tracking Prevention (ITP) limits most first-party cookies to seven days, regardless of stated retention policies. This means marketers must design data strategies that account not just for legal requirements, but also for technical constraints imposed by browsers.

Beyond compliance, cookie consent reflects a broader shift in consumer expectations. People want to understand what data is being collected, for what purpose, and for how long. Brands that are clear and respectful about these choices tend to build more trust over time, while those that aren’t risk eroding confidence before a customer ever subscribes or converts.

Cookie consent also has real implications for marketing performance. First-party data collected through cookies—such as on-site behaviour—supports personalisation, measurement, and optimisation, but only when collected within clearly defined purposes and timeframes. Paired with zero-party data that customers intentionally share through forms, quizzes, or preferences, it becomes part of a more durable, consent-aware foundation for modern marketing.

Benefits of collecting proper cookie consent

Implementing cookie consent thoughtfully can offer clear advantages for your business and your marketing practices, such as:

  • Legal protection:Proper consent documentation helps reduce the risk of regulatory fines and legal issues associated with data protection laws.
  • Stronger customer trust:Transparent data practices show that you respect your audience and are working to build a foundation for long-term customer relationships.
  • More control over your marketing: Strong first-party data and consent practices let you understand how people engage with your site, even before they identify themselves, so when they do sign up or check out, you can deliver more relevant, personalised experiences straight away.

Key features of cookie consent collection

Collecting cookie consent involves several components that work together to support privacy and consent compliance while maintaining a positive user experience:

  • Cookie consent banner: This appears when visitors first land on your site to explain which cookies you use and to ask for their permission to do so.
  • Cookie policy: The banner or pop-up links to this policy, which explains in detail which cookies your site uses, what data you’re collecting, how long the cookies last, and how visitors can manage their preferences.
  • Granular preference controls: These let visitors choose which types of cookies they accept, such as functional or analytics cookies, rather than forcing an all-or-nothing decision. A dedicated page allows visitors to review and update their cookie preferences at any time.
  • Consent management: A back-end log records when and how each visitor gives consent to create an audit trail for compliance.
  • Geo-targeting:Location detection allows you to show different consent experiences based on visitor location and specific regional laws. Data privacy laws vary significantly around the world, and your cookie consent approach needs to reflect where your visitors are located.

What cookies track—and which ones require consent

Privacy laws don’t define strict cookie categories, but they do require businesses to clearly explain the purpose of data collection so users understand what they’re agreeing to. In practice, most organisations group cookies into three core categories based on whether consent is required:

  • Strictly necessary (functional) cookies: These cookies enable essential site functionality, such as page navigation, secure logins, and shopping basket persistence. Because they are required for the site to operate, they typically do not require user consent, but they still must be disclosed.
  • Analytics cookies: These cookies help you understand how visitors interact with your site, such as which pages they view, how long they stay, or the paths they take through your site. Because they collect behavioural data that isn’t essential for the site to function, they generally do require consent in regions such as the EU.
  • Marketing cookies: These cookies track user behaviour to support advertising, retargeting, and personalised messaging, often across websites or platforms. This includes cookies set by ad networks, marketing tools, or social platforms. Marketing cookies almost always require explicit consent, as they involve profiling or data sharing.

Rather than focusing on who sets the cookie (for example, “social media cookies”), this approach emphasises why the data is collected. A single platform—like Google—may set multiple cookies that fall into different categories, such as analytics or marketing, each with its own consent requirement. Clear purpose-based categorisation helps users make informed choices and helps businesses stay compliant across regions.

Best practices for cookie consent

Getting cookie consent right requires balancing compliance with user experience. Here are some practical tips to help you succeed:

  • Keep it simple.Use plain language that anyone can understand, not confusing legal jargon.
  • Make choices clear. Present options honestly without using design tricks to manipulate visitors into accepting.
  • Load cookies after consent.Set non-essential cookies only after visitors have given permission.
  • Test your implementation.Audit your site regularly to confirm cookies are functioning correctly and consent is being recorded properly.
  • Keep your policy up to date.Review your cookie policy whenever you add new tracking tools or change how you use data.

How Klaviyo cookies and Extended ID help you track and personalise onsite

Klaviyo uses a first-party identity cookie to capture visitor activity on your site, which allows you to link behaviour—such as browsing, product views, and engagement—to a profile once someone identifies themselves by signing up, clicking a campaign link, or completing checkout. This creates a persistent view of how people interact with your brand over time and enables more relevant segmentation and personalisation.

With Extended ID, Klaviyo takes this further by extending the lifespan of these first-party identifiers—holding them for up to a year—which helps your business re-identify visitors long after their standard cookie would expire. This means you can retain historical context about returning visitors and better tailor your flows, recommendations, and messaging based on past activity, not just the moment someone identifies themselves.

Cookie consent helps you build a marketing foundation based on trust, transparency, and high-quality first-party data.

Ready to collect and activate customer data the right way? Get started with Klaviyo today.