This article is part of the Iris Ethics Knowledge Base; you can find a directory of all articles here.
Overview
Most online survey platforms collect IP addresses automatically, whether or not a researcher intends to use them. IP addresses can be handled ethically and lawfully if researchers understand why the data exists, use it only for a defined purpose, and delete it promptly once that purpose is served. This article sets out the identifiability question, the relevant privacy law, and a practical framework for managing IP data in an ethics application.
Identifiability is a continuum, not a category
The National Statement does not treat data as simply "identifiable" or "not identifiable"; identifiability exists on a continuum that depends on context (NS 3.1, Element 4). IP addresses illustrate why. Tracing an IP address to a specific individual generally requires cooperation from an internet service provider, precise timestamp correlation, and often a warrant. In practice this is difficult, and it is made harder by dynamic IP allocation (many providers rotate addresses regularly), network address translation on mobile and public networks (which lets many users share one visible address), and the use of VPNs or other privacy tools that mask a participant's actual address. IP-based geolocation typically resolves to an internet provider's infrastructure rather than the participant's physical location.
None of this means an IP address is never personal information. The Office of the Australian Information Commissioner treats information as personal information where it could reasonably identify someone, and the prudent approach is to treat IP addresses accordingly rather than assume they are automatically safe. What the continuum does support is a proportionate response: a low but real identifiability risk, managed through defined use and prompt deletion, rather than treatment as equivalent to a participant's name.
What the National Statement expects
NS 3.1.39 recognises that removing personal identifiers is not always ethically required; some projects legitimately need to retain identifiers, for example to link data from multiple sources or return results to participants. Quality control, including detecting duplicate responses and bot or fraudulent traffic, is a legitimate purpose of this kind, and IP addresses are a practical tool for it when reviewed alongside other indicators such as response timing and patterns.
NS 3.1.40 directs researchers to adopt methods that reduce identifiability during collection, analysis, and storage, including separating identifiers from content information and minimising the number of variables collected for each individual. Applied to IP addresses, this means collecting them for a specific quality-control purpose, keeping them separate from substantive response data, and removing them before analysis begins rather than carrying them through the dataset indefinitely. NS 2.2.6(f) requires that consent processes explain how privacy and confidentiality will be protected, which for online surveys should include a plain-language statement about IP collection and when it will be deleted.
Privacy Act considerations
At a general level, the Privacy Act 1988 (Cth) and the Australian Privacy Principles treat information as personal information where it can reasonably identify an individual, which can include an IP address depending on context. Researchers and evaluators handling participant data, including IP addresses, should consider their obligations under the Act alongside National Statement requirements; the two frameworks operate in parallel; see Privacy and identifiability for the broader concepts of identified, de-identified, re-identifiable, non-identifiable, and coded data that both frameworks draw on. Specific questions about how the Privacy Act applies to a particular data holding are a matter for the applicant's own privacy advice, not something an HREC can resolve as part of ethical review.
A practical framework for applications
Ethics applications involving online surveys should address IP address handling explicitly, rather than leaving it unmentioned:
- Acknowledge that the survey platform collects IP addresses automatically as part of its standard operation
- State the purpose: typically quality control, such as detecting duplicate submissions or automated responses
- Specify when IP data will be deleted, typically immediately after quality checks are complete and before substantive analysis begins
- Describe how IP data is kept separate from response content in storage
- Include a plain-language statement in participant information materials, for example: "Your IP address is automatically collected by our survey platform for quality control purposes only, to prevent duplicate responses and ensure data integrity. This information is deleted immediately after quality checks are completed and will not be included in any analysis or reporting."
Longer retention is occasionally justified, for example to document a suspected fraud incident for an institution or funder, but the default position is deletion after quality checks, and any departure from that default should be justified in the application. IP addresses are generally a poor tool for tracking participants across survey waves in longitudinal research, given how often addresses change; a proper participant identification system is a better approach where re-contact is needed.
Related resources
This page was last updated on 16 September 2026.
Was this helpful? We'd appreciate your feedback!
This article makes reference to the National Statement on Ethical Conduct in Human Research 2025. It is intended as practical guidance and does not constitute legal advice.
AI Disclosure: Resources in this library were prepared using Large Language Models with input from Iris Ethics staff who guided the scope and design. Subsequent revisions and final versions were developed and approved by Iris Ethics staff.