Ensuring your business is GDPR compliant↗ is of the utmost importance for any website operating in the EU or serving EU customers. This includes understanding the difference between UK and EU GDPR. Being aware of what GDPR requires means you can easily avoid fines↗ and penalties. Under GDPR, there are several requirements that govern how a business can process consumer data. One of these requirements covers the use of website cookies. While there are many types of cookies out there, only a few fall into the category of "strictly necessary".
What Are Strictly Necessary Cookies?
Strictly necessary cookies are cookies exempted from informed consent because they must be present for the website's core functionality. This includes cookies used for services the users have explicitly agreed to use. Because these cookies are exempt from cookie consent, the website can use them for the necessary purpose as soon as the user first interacts with the website. All other cookies must be blocked until the user agrees to their use.
Criteria for Cookie Consent Exemptions
These cookies are only strictly necessary if they meet certain strict criteria regarding what is necessary for core functionality and what is not. Examples of strictly necessary cookies include cookies used for first-party session recording, account logins, shopping cart storage, and online billing. Cookies that record user interaction for metrics, advertising, tracking, and other purposes not considered essential won't fit these criteria, unless the user has specifically given permission to use these cookies by explicitly requesting a service that these cookies are necessary for.
How to Audit Your eCommerce Stack for Strictly Necessary Cookies
Your Shopify store, payment processor, and analytics tools all inject cookies into your checkout flow. Before you can claim a cookie is strictly necessary, you need to know what's actually running on your site.
Start by mapping your tech stack. List every third-party service connected to your store: Shopify's built-in session cookies, Klaviyo for email capture, Meta Pixel for retargeting, Google Analytics, your payment gateway (Stripe, PayPal, Square), shipping calculators, live chat, and any other integrations.
Next, use your browser's developer tools to audit what cookies are set. Visit your homepage, add something to your cart, and go through checkout. Document each cookie: its name, which service created it, when it expires, and what it does.
Then ask yourself: Does the user lose a critical function without this cookie? A session cookie that keeps someone logged in? Necessary. A cookie that remembers they added a product to their cart? Necessary. A cookie that tracks which products they viewed for retargeting ads? Not necessary.
This audit forces honesty. Many eCommerce brands discover they're running more non-essential tracking than they realized. You might find that your analytics tool is set to fire cookies before consent—a common compliance gap. Documenting everything also protects you if a regulator asks what cookies you use and why.
The Gray Zone: Legitimate Interest vs. Strictly Necessary
GDPR allows processing under "legitimate interest" as an alternative legal basis to consent. This creates confusion: if you claim a cookie is strictly necessary when it isn't, you're breaking GDPR. But if you properly document a legitimate interest—like fraud prevention or payment processing—you may process some cookies without consent, provided you meet specific balancing tests.
Here's where many eCommerce brands get stuck. Your payment provider (like Stripe or PayPal) uses cookies for fraud detection and PCI compliance. These are genuinely necessary for processing payments safely. But your analytics tool might argue that understanding user behavior prevents cart abandonment, which protects revenue. That's not the same thing.
The distinction matters operationally. A strictly necessary cookie doesn't require a consent banner. A legitimate interest cookie may require a banner and a legitimate interest assessment (LIA). Some brands opt to get explicit consent instead—simpler, but means lower opt-in rates.
For your eCommerce store, focus this way: Payment and security cookies are strictly necessary. Cookies that improve user experience (remembering preferences, keeping you logged in, load balancing) are strictly necessary. Cookies that enable marketing, behavioral analysis, or advertising are not—even if they technically improve conversion rates.
Document your reasoning. If a regulator asks why you didn't ask for consent, you want to show clear logic, not a guess.
Building a Compliant Checkout Without Breaking Conversion
Your checkout is a hotbed of cookie conflicts. You need session cookies, CSRF tokens, and payment tokens to work. But you also want to personalize recommendations and track funnel drop-off.
The practical path: Allow strictly necessary cookies to load immediately. This includes Shopify's session token, your payment processor's payment token, and any CSRF protection. Your checkout works.
Then, after the user consents, load marketing and analytics pixels. This means your Meta Pixel and Google Analytics fire after the purchase completes, not during it. You lose some mid-funnel data, but you stay compliant.
Some brands use a two-step banner: a simple "Required to complete your order" message for necessary cookies, then a secondary consent request for analytics. This can improve conversion because users see the first prompt as unavoidable and the second as optional.
Test this flow. Many eCommerce managers assume a split approach hurts conversion, but the data often shows minimal impact—users who want to buy will click through your consent banner. Users who don't consent to analytics were unlikely to see ads anyway.
Common Mistakes That Expose eCommerce Brands to Enforcement Risk
Many mid-market eCommerce brands fall into predictable traps. You label cookies as "strictly necessary" without actually testing whether the site breaks without them. You load Google Analytics before consent because it "doesn't matter." You hide your cookie policy four links deep in the footer.
These gaps are exactly what regulators look for. If your banner claims a cookie is necessary, but your site works fine without it, you've made a false statement under GDPR.
Another mistake: assuming your CMS or Shopify app handles compliance automatically. Some cookie consent apps are poorly configured—they still load pixels before consent or don't actually block anything. Spot-check your setup.
Running a compliant eCommerce store requires ongoing attention to how cookies interact with your conversion funnel. As your tech stack grows, so does the risk of misconfigured trackers and unaudited third-party scripts. A proper consent management system can enforce your policies automatically, rather than relying on manual compliance checks that get overlooked during high-volume sales periods.