Can US and European business units share an IP address under GDPR?
Matthew Whittaker
Co-founder & CTO, Suped
Published 4 Aug 2025
Updated 16 Aug 2025
7 min read
The question of whether US and European business units can share an IP address under the General Data Protection Regulation (GDPR) is a nuanced one. On the surface, it might seem like a simple technical query, but it quickly delves into complex legal and data privacy territory. Many organizations grapple with this, especially those operating internationally and managing email sending infrastructure across different geographical locations.
My experience in email deliverability and compliance often brings me into contact with scenarios where technical setups intersect with regulatory requirements. While sharing an IP address might be technically feasible, the GDPR's broad scope and definition of personal data mean that careful consideration is necessary to ensure compliance and avoid potential penalties.
GDPR's extraterritorial reach and IP addresses
The GDPR is known for its extraterritorial reach, meaning it applies beyond the physical borders of the European Union. If a business, regardless of its location (e.g., in the US), processes the personal data of individuals who are in the EU, then GDPR compliance is mandatory. This includes activities like offering goods or services to EU residents, or monitoring their behavior within the EU. Understanding this scope is the first critical step.
A key point of contention is whether an IP address constitutes personal data under GDPR. The consensus, reinforced by rulings from the Court of Justice of the European Union, is that an IP address, especially when combined with other data, can indeed be considered personal data. This is because it can be used to identify an individual, directly or indirectly. As a result, any processing or storage of IP addresses, including those related to email sending, falls under GDPR's protective umbrella. You can find more details about this specific classification on CookieYes' blog on IP addresses and GDPR.
Given that IP addresses are personal data, the sharing of an IP address between a US and European business unit means that the data associated with that IP must be handled in full compliance with GDPR for all EU residents. This implies adherence to principles like lawful processing, purpose limitation, data minimization, accuracy, storage limitation, integrity, and confidentiality. It also brings into play considerations around cross-border data transfers, which are a cornerstone of GDPR compliance for international businesses.
Shared IP addresses and their intersection with GDPR
From a purely technical standpoint, there's no inherent reason why US and European business units can't share an IP address for sending emails. Many email service providers (ESPs) offer shared IP addresses where multiple senders use the same IP. The challenge isn't the technical possibility, but the legal implications of doing so when dealing with GDPR-protected data. The core issue lies in how data, including IP addresses, is collected, processed, and stored across jurisdictions.
If you're using a shared IP address, especially one managed by a third-party ESP, it's crucial to understand their data handling practices. If an IP is shared, and it is used to send emails to EU citizens, then GDPR applies to the data associated with those emails and the IP itself. This includes not just the initial sending, but also any logging, tracking, or storage of those IP addresses. The responsibility to ensure GDPR compliance ultimately rests with the data controller, even if a processor handles the technical aspects.
Technical aspects of shared IPs
Multiple business units can technically use the same IP address for email sending, often through a common email service provider. This setup can simplify infrastructure and potentially reduce costs.
The deliverability impact of shared IP addresses is a separate concern, related to the sending reputation of other users on that IP, but not directly a GDPR issue in itself.
GDPR compliance for shared IPs
If the shared IP is used to process data of EU residents, GDPR applies to all data associated with that IP, including IP logs. This necessitates a lawful basis for processing.
Ensuring proper data protection agreements (DPAs) with any third-party ESPs is crucial, as they act as data processors under GDPR rules.
Data storage location and transfer mechanisms
Beyond the IP address itself, the critical GDPR consideration for international businesses is where the data of EU data subjects is stored and processed. If a US business unit shares an IP address and sends emails to EU residents, the personal data (including the IP address) will likely be logged and stored. The location of these logs and other associated data is paramount.
Transferring personal data outside the EU, especially to a country like the US that does not have an EU adequacy decision for its general data protection framework, requires specific legal safeguards. These typically include Standard Contractual Clauses (SCCs), Binding Corporate Rules (BCRs), or reliance on frameworks like the EU-US Data Privacy Framework (which replaced Privacy Shield). Merely sharing an IP does not exempt you from these transfer requirements if EU data is involved and processed in the US.
Cross-border data transfer considerations
When US and EU business units share an IP, and this results in personal data of EU residents being processed or stored outside the EU, robust data transfer mechanisms are essential. This could involve reliance on Standard Contractual Clauses (SCCs), or ensuring the US entity is certified under the EU-US Data Privacy Framework. It is not just the IP, but all associated data, that matters.
Mitigating risks and ensuring compliance
To navigate this complexity, the safest approach for businesses operating in both the US and Europe is to assume that all data processed via a shared IP address (or any other means) that might involve EU residents is subject to GDPR. This highest common denominator strategy simplifies compliance efforts. It means implementing GDPR-level data protection across the board, even for data that might originate from US-based interactions but share an infrastructure with EU-facing operations.
Legal advice: Always consult with legal counsel specializing in data privacy and GDPR. This article provides general information, not legal advice.
Data mapping: Understand where all personal data, including IP addresses, is collected, processed, and stored throughout its lifecycle.
Data processing agreements (DPAs): Ensure all third-party vendors (like ESPs) have robust DPAs in place that align with GDPR requirements.
Transparency: Maintain clear and accessible privacy policies informing users about data collection, processing, and sharing, including IP addresses.
While sharing an IP address itself isn't prohibited, the underlying data practices must meet GDPR's stringent requirements if EU residents' data is involved. This includes implementing strong security measures, obtaining appropriate consent where necessary, and respecting data subject rights, regardless of where the data originates or resides within your global infrastructure.
Views from the trenches
Best practices
Always treat IP addresses as personal data under GDPR if there's any chance they relate to EU residents.
Implement robust data transfer mechanisms, such as SCCs or the EU-US Data Privacy Framework, for cross-border data flows.
Conduct regular data protection impact assessments (DPIAs) to identify and mitigate risks associated with data processing.
Ensure clear communication with data subjects about how their data, including IP addresses, is being processed.
Common pitfalls
Assuming GDPR does not apply because your company is based in the US and lacks a physical EU presence.
Overlooking the logging of IP addresses by ESPs or internal systems as personal data that needs protection.
Failing to establish proper data processing agreements (DPAs) with all third-party vendors.
Not accounting for data residency requirements and transfer safeguards for EU data.
Expert tips
Prioritize GDPR compliance for all data, adopting the highest standard across all your business units for simplicity and safety.
Regularly review your data processing activities and adjust your strategies to stay compliant with evolving privacy regulations.
Educate your teams, especially those in marketing and IT, on GDPR's implications for IP addresses and email data.
Utilize compliance tools and legal counsel to verify that your shared IP setup aligns with international data privacy laws.
Marketer view
Marketer from Email Geeks says there is no technical reason why a shared IP address would not be possible, provided the IP is associated with a common sending service or ESP used by both parties.
2021-03-31 - Email Geeks
Marketer view
Marketer from Email Geeks says that if there are compliance issues, they are likely less about the IP address itself and more about where the data is stored.
2021-03-31 - Email Geeks
Navigating shared IPs and GDPR
In summary, while there are no technical barriers to US and European business units sharing an IP address for email sending, the General Data Protection Regulation (GDPR) imposes significant legal obligations. The key takeaway is that an IP address, when linked to an individual, is considered personal data under GDPR.
Therefore, any such sharing must be accompanied by comprehensive GDPR compliance measures, particularly concerning cross-border data transfers and the overarching principles of data protection. Consulting with legal experts is essential to ensure your specific setup meets all regulatory requirements and avoids potential blocklist (or blacklist) issues arising from compliance failures.
