Data breaches, cybersecurity professionals' biggest nightmares, can happen at any time. While big companies are able to employ specialists to guard against this, beginner eCommerce stores likely won't have the expertise to handle sophisticated threats without outside help. Either way, it's important to ensure GDPR compliance↗ when a data breach occurs. According to GDPR, a personal data breach occurs when accidental or unlawful destruction, loss, alteration, unauthorized disclosure of, or access to personal data transmitted, stored, or otherwise processed occurs. The biggest threat is when malicious actors breach security and steal personal data, which they then sell or use for other illegal activities.
What Is Considered "Personal Data" Under GDPR?
It's important to determine what GDPR considers to be personal data to remain compliant in a potential data breach. The following types of information relating to a natural person are considered personal data:
- Name
- Identification number
- Location data
- IP address
- Cookie identifiers
The purposeful or accidental disclosure of any confidential information is regarded as a data breach by GDPR↗. This includes information relating to a person's physical, physiological, genetic, mental, economic, cultural, or social identity as well as contact information (including sharing email addresses↗). Be sure to read up on the difference between personal vs private data↗ too and how those relate to personally identifiable information (PII).
Conclusion
Any website or business that collects, stores, or processes information is responsible for maintaining compliance with GDPR. There can be severe penalties for non-compliance, so it's important to continually place your own business under review to avoid them.
How Data Breaches Happen in eCommerce Operations
Your eCommerce store collects customer data at multiple touchpoints — checkout, account creation, email marketing signups, and customer service inquiries. Each of these creates a potential entry point for breach.
Common scenarios that trigger GDPR breaches in mid-market eCommerce:
Payment processing gaps: If you store credit card data beyond the moment needed for a transaction, you're creating unnecessary risk. Your Shopify or BigCommerce store should never store raw card numbers — payment processors handle this. If your team exports customer lists to CSV files and leaves them unencrypted on shared drives, that's a breach waiting to happen.
Third-party tool misconfigurations: You likely use Klaviyo for email, Meta Pixel for retargeting, and Google Analytics for traffic data. If these tools are misconfigured, they can leak customer information to ad networks or analytics platforms without proper consent. A misconfigured Meta Pixel, for instance, can send email addresses and phone numbers to Facebook when you didn't intend it to.
Abandoned customer data: Old customer lists sitting on personal laptops, forgotten cloud storage accounts, or backup servers create lingering exposure. When your team leaves or you switch email platforms, that data needs deliberate deletion — not just archiving.
Weak access controls: If every team member has password access to your customer database, or if you reuse passwords across platforms, a single compromised employee account can expose thousands of customer records.
The breach doesn't have to be dramatic — a misconfigured server, an unencrypted backup, or overly permissive file-sharing settings all count as unauthorized access under GDPR.
Your Notification Obligations After a Breach
GDPR gives you a strict timeline: you must notify your data protection authority (DPA) within 72 hours of discovering a breach, unless the breach poses no risk to customer rights and freedoms.
Here's where many eCommerce brands stumble. You need to:
Document the discovery date precisely: Not when it happened, but when you first learned about it. If your developer finds a misconfigured API endpoint on a Tuesday, the 72-hour clock starts then, even if the breach began weeks earlier.
Assess the actual risk: A breach involving payment data is high-risk. A breach involving only public information (like published reviews) is lower-risk. GDPR lets you skip DPA notification if you can genuinely demonstrate minimal risk — but the burden of proof is yours, and regulators scrutinize this claim heavily.
Notify affected customers if the breach is high-risk: You must tell customers in plain language what happened, what data was involved, and what steps they should take. A generic "we experienced a security incident" email won't cut it. Be specific: "Customer email addresses and purchase history were accessed" is clearer than vague language.
Keep records: Document everything — when you discovered the breach, how you assessed risk, what notifications you sent, and when. If a regulator investigates later, these records prove you took it seriously.
Many eCommerce brands skip the DPA notification because they assume they're "too small" to matter. That's a costly mistake. Regulators actively investigate breaches at mid-market retailers, and fines for delayed or missing notifications can run into tens of thousands of euros.
Preventing Breaches Before They Happen
The best compliance strategy is preventing breaches in the first place.
Limit data collection: Don't ask for information you don't need. If you don't need a customer's phone number, don't ask for it. Less data stored means less data at risk.
Encrypt data in transit and at rest: Any customer data moving across the internet or sitting in your database should be encrypted. This is table stakes for eCommerce — your hosting provider should handle encryption in transit (HTTPS), but you need to confirm your database is encrypted too.
Use vendor due diligence: Before connecting Klaviyo, Gorgias, or any third-party tool to your Shopify store, confirm they have written data processing agreements (DPAs) in place. These contracts clarify who's responsible for data security and breach notification.
Segregate sensitive data: Payment data shouldn't live in your marketing database. Customer names and addresses shouldn't be exported to personal spreadsheets. Use role-based access — your marketing team needs email addresses, not full customer profiles.
Regular security audits: Hire a third party to review your systems annually, especially if you're processing thousands of transactions monthly. They'll spot misconfigurations your team might miss.
Train your team: Most breaches involve human error — a phishing email, a forgotten password, oversharing. Annual privacy training for your whole team costs far less than a breach investigation.
Creating a Breach Response Plan Today
Don't wait for a breach to figure out your response. Write a one-page breach response plan now, while you have time to think clearly.
Your plan should name:
- Who discovers breaches (your IT person, hosting provider, or payment processor)
- Who decides if it's a GDPR breach (usually your data protection officer or compliance lead)
- Who notifies the DPA (with contact details for your national regulator)
- Who contacts customers (with draft email templates)
- Who handles media inquiries (if the breach becomes public)
Share this plan with your team and your vendors. If your hosting provider discovers a breach, they need to know exactly how to reach you within hours, not days.
A documented plan also signals to regulators that you take data security seriously — even if a breach eventually happens, your prompt and organized response can meaningfully reduce penalties.
Your brand's reputation depends partly on how you handle a breach, not just whether one occurs. Customers forgive security incidents less often than they forgive poor communication about them.
The tighter your data handling practices and the faster your breach response, the easier you'll find it to meet GDPR obligations — and to prove compliance to regulators. However, managing consent, tracking data flows, and maintaining breach readiness across multiple platforms becomes complex as you grow. The right privacy infrastructure can automate notification requirements, audit your tool integrations, and centralize your response protocols all in one place.