Personal data, also known as personal information or personally identifiable information (PII),
is any information related to an identifiable person.
The abbreviation PII is widely used in the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
, but the phrase it abbreviates has four common variants based on ''personal'' or ''personally'', and ''identifiable'' or ''identifying''. Not all are equivalent, and for legal purposes the effective definitions vary depending on the jurisdiction and the purposes for which the term is being used. Under
European Union
The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...
and
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...
data protection regimes, which centre primarily on the
General Data Protection Regulation (GDPR), the term "personal data" is significantly broader, and determines the scope of the regulatory regime.
National Institute of Standards and Technology
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into Outline of p ...
Special Publication 800-122
defines personally identifiable information as "any information about an individual maintained by an agency, including (1) any information that can be used to distinguish or trace an individual's identity, such as name, social security number, date and place of birth, mother's maiden name, or
biometric records; and (2) any other information that is linked or linkable to an individual, such as medical, educational, financial, and employment information." For instance, a user's
IP address
An Internet Protocol address (IP address) is a numerical label such as that is assigned to a device connected to a computer network that uses the Internet Protocol for communication. IP addresses serve two main functions: network interface i ...
is not classed as PII on its own, but is classified as a linked PII.
Personal data is defined under the GDPR as "any information which
srelated to an identified or identifiable natural person".
The IP address of an Internet subscriber may be classed as personal data.
The concept of PII has become prevalent as
information technology
Information technology (IT) is a set of related fields within information and communications technology (ICT), that encompass computer systems, software, programming languages, data processing, data and information processing, and storage. Inf ...
and the
Internet
The Internet (or internet) is the Global network, global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a internetworking, network of networks ...
have made it easier to collect PII leading to a profitable market in collecting and reselling PII. PII can also be exploited by criminals to
stalk or
steal the identity of a person, or to aid in the planning of criminal acts. As a response to these threats, many website
privacy policies specifically address the
gathering of PII, and lawmakers such as the
European Parliament
The European Parliament (EP) is one of the two legislative bodies of the European Union and one of its seven institutions. Together with the Council of the European Union (known as the Council and informally as the Council of Ministers), it ...
have enacted a series of legislation such as the GDPR to limit the distribution and accessibility of PII.
Important confusion arises around whether PII means information which is identifiable (that is, can be associated with a person) or identifying (that is, associated uniquely with a person, such that the PII ''identifies'' them). In prescriptive data privacy regimes such as the US federal
Health Insurance Portability and Accountability Act
The Health Insurance Portability and Accountability Act of 1996 (HIPAA or the Ted Kennedy, Kennedy–Nancy Kassebaum, Kassebaum Act) is a United States Act of Congress enacted by the 104th United States Congress and signed into law by President ...
(HIPAA), PII items have been specifically defined. In broader data protection regimes such as the GDPR, personal data is defined in a non-prescriptive principles-based way. Information that might not count as PII under HIPAA can be personal data for the purposes of GDPR. For this reason, "PII" is typically deprecated internationally.
Definitions
The
U.S
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
. government used the term "personally identifiable" in 2007 in a memorandum from the
Executive Office of the President,
Office of Management and Budget
The Office of Management and Budget (OMB) is the largest office within the Executive Office of the President of the United States (EOP). The office's most prominent function is to produce the president's budget, while it also examines agency pro ...
(OMB),
[M-07-16 SUBJECT:Safeguarding Against and Responding to the Breach of Personally Identifiable Information](_blank)
from Clay Johnson III, Deputy Director for Management (2007/05/22) and that usage now appears in US standards such as the
NIST
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical s ...
''Guide to Protecting the Confidentiality of Personally Identifiable Information'' (SP 800-122).
The OMB memorandum defines PII as follows:
A term similar to PII, "personal data", is defined in EU directive 95/46/EC, for the purposes of the directive:
In the
EU rules, there has been a more specific notion that the data subject can potentially be identified through additional processing of other attributes—quasi- or pseudo-identifiers. In the GDPR, personal data is defined as:
A simple example of this distinction: the color name "red" by itself is ''not'' personal data, but that same value stored as part of a person's record as their "favorite color" ''is'' personal data; it is the connection to the person that makes it personal data, not (as in PII) the value itself.
Another term similar to PII, "personal information", is defined in a section of the California data breach notification law, SB1386:
The concept of information combination given in the SB1386 definition is key to correctly distinguishing PII, as defined by OMB, from "personal information", as defined by SB1386. Information, such as a name, that lacks context cannot be said to be SB1386 "personal information", but it must be said to be PII as defined by OMB. For example, the name "
John Smith" has no meaning in the current context and is therefore not SB1386 "personal information", but it is PII. A
Social Security Number
In the United States, a Social Security number (SSN) is a nine-digit number issued to United States nationality law, U.S. citizens, Permanent residence (United States), permanent residents, and temporary (working) residents under section 205(c)(2 ...
(SSN) without a name or some other associated identity or context information is not SB1386 "personal information", but it is PII. For example, the SSN 078-05-1120 by itself is PII, but it is not SB1386 "personal information". However the combination of a valid name with the correct SSN is SB1386 "personal information".
The combination of a name with a context may also be considered PII; for example, if a person's name is on a list of patients for an HIV clinic. However, it is not necessary for the name to be combined with a context in order for it to be PII. The reason for this distinction is that bits of information such as names, although they may not be sufficient by themselves to make an identification, may later be combined with other information to identify persons and expose them to harm.
The scope of the term "sensitive personal data" varies by jurisdiction. In the UK, personal
health data
Health data is any data "related to health conditions, reproductive outcomes, Cause of death, causes of death, and Quality of life (healthcare), quality of life" for an individual or population. Health data includes clinical metrics ...
is treated as "sensitive" and in need of additional data protection measures. According to the OMB, in the United States it is not always the case that PII is "sensitive", and context may be taken into account in deciding whether certain PII is or is not sensitive.
When a person wishes to remain anonymous, descriptions of them will often employ several of the above, such as "a 34-year-old white male who works at Target". Information can still be ''private'', in the sense that a person may not wish for it to become publicly known, without being personally identifiable. Moreover, sometimes multiple pieces of information, none sufficient by itself to uniquely identify an individual, may uniquely identify a person when combined; this is one reason that multiple pieces of evidence are usually presented at criminal trials. It has been shown that, in 1990, 87% of the population of the United States could be uniquely identified by gender,
ZIP code, and full date of birth.
In
hacker
A hacker is a person skilled in information technology who achieves goals and solves problems by non-standard means. The term has become associated in popular culture with a security hackersomeone with knowledge of bug (computing), bugs or exp ...
and
Internet slang, the practice of finding and releasing such information is called "
doxing". It is sometimes used to deter collaboration with law enforcement. On occasion, the doxing can trigger an arrest, particularly if law enforcement agencies suspect that the "doxed" individual may panic and disappear.
Laws and standards
Australia
In Australia, the
Privacy Act 1988 deals with the protection of individual privacy, using the OECD Privacy Principles from the 1980s to set up a broad, principles-based regulatory model (unlike in the US, where coverage is generally not based on broad principles but on specific technologies, business practices or data items). Section 6 has the relevant definition. The critical detail is that the definition of 'personal information' also applies to where the individual can be indirectly identified:
It appears that this definition is significantly broader than the Californian example given above, and thus that Australian privacy law may cover a broader category of data and information than in some US law.
In particular, online
behavioral advertising businesses based in the US but surreptitiously collecting information from people in other countries in the form of cookies,
bugs, trackers and the like may find that their preference to avoid the implications of wanting to build a
psychographic profile of a particular person using the rubric of 'we don't collect personal information' may find that this does not make sense under a broader definition like that in the Australian Privacy Act.
The term "PII" is not used in Australian privacy law.
Canada
* The
Privacy Act governs the federal government agencies
* The
Ontario Freedom of Information and Protection of Privacy Act and similar provincial legislation governs provincial government agencies
* The
Personal Information Protection and Electronic Documents Act governs private corporations, unless there is equivalent provincial legislation
*
Ontario Personal Health Information Protection Act and other similar provincial legislation governs health information
European Union
European Union data protection law does not use the concept of personally identifiable information, and its scope is instead determined by non-synonymous, wider concept of "personal data".
*
Article 8 of the European Convention on Human Rights
*
Convention for the Protection of Individuals with Regard to Automatic Processing of Personal Data
* The
General Data Protection Regulation adopted in April 2016; effective 25 May 2018
** supersedes the Data Protection Directive, 95/46/EC
* The
Directive on Privacy and Electronic Communications, 2002/58/EC (the E-Privacy Directive)
* The
Data Retention Directive, 2006/24/EC, Article 5
Further examples can be found on the EU privacy website.
Hong Kong
On 1 June 2023, the Hong Kong Office of the Privacy Commissioner for Personal Data published an investigation report on a data breach involving the unauthorised access of a credit reference database platform. The Report highlights the need for organizations to take adequate steps to protect personal data as the mere imposition of contractual obligations and policies is insufficient if such obligations and policies are not effective or are not enforced. The Report also clarifies that credit data is a form of "sensitive" personal data.
United Kingdom
* The
Data Protection Act 2018, which in part implements the GDPR
** supersedes the
Data Protection Act 1998
*
UK GDPR, retained EU law, substantially the same as the EU GDPR with necessary amendments due to
Brexit
Brexit (, a portmanteau of "Britain" and "Exit") was the Withdrawal from the European Union, withdrawal of the United Kingdom (UK) from the European Union (EU).
Brexit officially took place at 23:00 GMT on 31 January 2020 (00:00 1 February ...
*
Article 8 of the European Convention on Human Rights
* The
Regulation of Investigatory Powers Act 2000
* Employers' Data Protection Code of Practice
* Model Contracts for Data Exports
* The
Privacy and Electronic Communications (EC Directive) Regulations 2003
* The Telecommunications (Lawful Business Practice) (Interception of Communications) Regulations 2000
* The
Anti-Terrorism, Crime and Security Act 2001
New Zealand
The twelve Information Privacy Principles of the
Privacy Act 1993 apply. New Zealand enacted the Privacy Act in 2020 to promote and protect individual privacy.
Switzerland
The
Federal Act on Data Protection of 19 June 1992 (in force since 1993) has set up a protection of privacy by prohibiting virtually any processing of personal data which is not expressly authorized by the data subjects.
[Federal Act on Data Protection of 19 June 1992 (status as of 1 January 2014)]
Federal Chancellery of Switzerland
The Federal Chancellery of Switzerland is a department-level agency of the federal administration of Switzerland. It is the staff organisation of the federal government, the Federal Council (Switzerland), Federal Council. Since 2024, it has bee ...
(page visited on 18 September 2016). The protection is subject to the authority of the
Federal Data Protection and Information Commissioner.
Additionally, any person may ask in writing a company (managing data files) the correction or deletion of any personal data.
[ Cesla Amarelle, ''Droit suisse'', Éditions Loisirs et pédagogie, 2008.] The company must respond within thirty days.
United States
The
Privacy Act of 1974
Privacy (, ) is the ability of an individual or group to seclude themselves or information about themselves, and thereby express themselves selectively.
The domain of privacy partially overlaps with security, which can include the concepts of ...
(Pub.L. 93–579, 88 Stat. 1896, enacted 31 December 1974, , a United States federal law, establishes a Code of Fair Information Practice that governs the collection, maintenance, use, and dissemination of personally identifiable information about individuals that is maintained in systems of records by federal agencies.
One of the primary focuses of the
Health Insurance Portability and Accountability Act
The Health Insurance Portability and Accountability Act of 1996 (HIPAA or the Ted Kennedy, Kennedy–Nancy Kassebaum, Kassebaum Act) is a United States Act of Congress enacted by the 104th United States Congress and signed into law by President ...
(HIPAA) is to protect a patient's
Protected Health Information
Protected health information (PHI) under Law of the United States, U.S. law is any information about health status, provision of health care, or payment for health care that is created or collected by a Covered Entity (or a Business Associate of a ...
(PHI), which is similar to PII. The U.S. Senate proposed the Privacy Act of 2005, which attempted to strictly limit the display, purchase, or sale of PII without the person's consent. Similarly, the (proposed) Anti-Phishing Act of 2005 attempted to prevent the acquiring of PII through
phishing.
U.S. lawmakers have paid special attention to the
social security number
In the United States, a Social Security number (SSN) is a nine-digit number issued to United States nationality law, U.S. citizens, Permanent residence (United States), permanent residents, and temporary (working) residents under section 205(c)(2 ...
because it can be easily used to commit
identity theft
Identity theft, identity piracy or identity infringement occurs when someone uses another's personal identifying information, like their name, identifying number, or credit card number, without their permission, to commit fraud or other crimes. ...
. The (proposed) Social Security Number Protection Act of 2005 and (proposed) Identity Theft Prevention Act of 2005 each sought to limit the distribution of an individual's social security number.
Additional U.S.-specific personally identifiable information includes, but is not limited to, I-94 records, Medicaid ID numbers, and Internal Revenue Service (I.R.S.) documentation. Exclusivity of personally identifiable information affiliated with the U.S. highlights national data security concerns and the influence of personally identifiable information in U.S. federal data management systems.
State laws and significant court rulings
* California
** The California state constitution declares privacy an inalienable right in Article 1, Section 1.
**
Online Privacy Protection Act (OPPA) of 2003
**
SB 1386 requires organizations to notify individuals when PII (in combination with one or more additional, specific data elements) is known or believed to be acquired by an unauthorized person.
** In 2011, the California State Supreme Court ruled that a person's ZIP code is PII.
* Nevada
** Nevada Revised Statutes 603A – Security of Personal Information
* Massachusetts
**
201 CMR 17.00: Standards for the Protection of Personal Information of Residents of the Commonwealth
** In 2013, the Massachusetts Supreme Court ruled that ZIP codes are PII.
Federal law
*
* The Privacy Act of 1974, codified at et seq.
*
EU–US Data Privacy Framework, EU harmonisation, adopted on 10 July 2023
** supersedes the
EU–US Privacy Shield, which was ruled invalid by the European Court of Justice in 2020
NIST definition
The
National Institute of Standards and Technology (NIST) is a physical sciences laboratory, and a non-regulatory agency of the United States Department of Commerce. Its mission is to promote innovation and industrial competitiveness.
The following data, often used for the express purpose of distinguishing individual identity, clearly classify as personally identifiable information under the definition used by the NIST (described in detail below):
*
National identification number (e.g.,
Social Security number
In the United States, a Social Security number (SSN) is a nine-digit number issued to United States nationality law, U.S. citizens, Permanent residence (United States), permanent residents, and temporary (working) residents under section 205(c)(2 ...
in the U.S.)
*
Bank account
A bank account is a financial account maintained by a bank or other financial institution in which the financial transaction
A financial transaction is an Contract, agreement, or communication, between a buyer and seller to exchange goods, ...
numbers
*
Passport
A passport is an official travel document issued by a government that certifies a person's identity and nationality for international travel. A passport allows its bearer to enter and temporarily reside in a foreign country, access local aid ...
number
*
Driver's license number
*
Debit/credit card numbers
The following are less often used to distinguish individual identity, because they are traits shared by many people. However, they are potentially PII, because they may be combined with other personal information to identify an individual.
* Full name
* Home address
* City
* State
*
Postcode
A postal code (also known locally in various English-speaking countries throughout the world as a postcode, post code, PIN or ZIP Code) is a series of letters or numerical digit, digits or both, sometimes including spaces or punctuation, inclu ...
* Country
*
Telephone
A telephone, colloquially referred to as a phone, is a telecommunications device that enables two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most ...
* Age, date of birth, especially if non-specific
*
Gender
Gender is the range of social, psychological, cultural, and behavioral aspects of being a man (or boy), woman (or girl), or third gender. Although gender often corresponds to sex, a transgender person may identify with a gender other tha ...
or race
*
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Forensics
In
forensics, particularly the identification and prosecution of criminals, personally identifiable information is critical in establishing evidence in
criminal procedure
Criminal procedure is the adjudication process of the criminal law. While criminal procedure differs dramatically by jurisdiction, the process generally begins with a formal criminal charge with the person on trial either being free on bail ...
. Criminals may go to great trouble to avoid leaving any PII, such as by:
* Wearing masks, sunglasses, or clothing to obscure or completely hide distinguishing features, such as
eye, skin, and hair colour, facial features, and personal marks such as tattoos, birthmarks, moles and scars.
* Wearing gloves to conceal
fingerprint
A fingerprint is an impression left by the friction ridges of a human finger. The recovery of partial fingerprints from a crime scene is an important method of forensic science. Moisture and grease on a finger result in fingerprints on surfa ...
s, which themselves are PII. However, gloves can also leave prints that are just as unique as human fingerprints. After collecting
glove prints, law enforcement can then match them to gloves that they have collected as evidence. In many
jurisdictions the act of wearing gloves itself while committing a crime can be prosecuted as an
inchoate offense
An inchoate offense, preliminary crime, inchoate crime or incomplete crime is a crime of preparing for or seeking to commit another crime. The most common example of an inchoate offense is "attempt". "Inchoate offense" has been defined as the fol ...
.
[James W.H. McCord and Sandra L. McCord, ''Criminal Law and Procedure for the paralegal: a systems approach'', ''supra'', p. 127.]
* Avoiding writing anything in their own
handwriting.
* Masking their internet presence with methods such as using a
proxy server to appear to be connecting from an
IP address
An Internet Protocol address (IP address) is a numerical label such as that is assigned to a device connected to a computer network that uses the Internet Protocol for communication. IP addresses serve two main functions: network interface i ...
unassociated with oneself.
Personal safety
Personal data is a key component of
online identity and can be exploited by individuals. For instance, data can be altered and used to create fake documents, hijack mail boxes and phone calls or harass people, as occurred in 2019 to a customer of the
EE mobile phone operator in the UK.
Another category can be referred to as financial identity theft, which usually entails bank account and credit card information being stolen, and then being used or sold.
Personal data can also be used to create fake online identities, including fake accounts and profiles (which can be referred as identity cloning or
identity fraud) for celebrities to gather data from other users more easily. Even individuals can be concerned, especially for personal purposes (this is more widely known as
sockpuppetry).
The most critical information, such as one's password, date of birth, ID documents or
social security number
In the United States, a Social Security number (SSN) is a nine-digit number issued to United States nationality law, U.S. citizens, Permanent residence (United States), permanent residents, and temporary (working) residents under section 205(c)(2 ...
, can be used to log in to different websites (e.g.
password reuse and
account verification) to gather more information and access more content.
Also, several agencies ask for discretion on subjects related to their work, for the safety of their employees. For this reason, the
United States Department of Defense
The United States Department of Defense (DoD, USDOD, or DOD) is an United States federal executive departments, executive department of the federal government of the United States, U.S. federal government charged with coordinating and superv ...
(DoD) has strict policies controlling release of personally identifiable information of DoD personnel. Many
intelligence agencies have similar policies, sometimes to the point where employees do not disclose to their friends that they work for the agency.
Similar identity protection concerns exist for
witness protection programs,
women's shelters, and victims of domestic violence and other threats.
Personal information removal
Trade of personal data
During the second half of the 20th century, the
digital revolution
The Information Age is a History by period, historical period that began in the mid-20th century. It is characterized by a rapid shift from traditional industries, as established during the Industrial Revolution, to an economy centered on info ...
introduced "privacy economics", or the trade of personal data. The value of data can change over time and over different contexts. Disclosing data can reverse
information asymmetry, though the costs of doing so can be unclear. In relation to companies, consumers often have "imperfect information regarding when their data is collected, with what purposes, and with what consequences".
Writing in 2015, Alessandro Acquisti, Curtis Taylor and Liad Wagman identified three "waves" in the trade of personal data:
#In the 1970s, the
Chicago Boys school claimed that protection of privacy could have a negative impact on the market because it could lead to incorrect and non-optimal decisions. Other researchers like Andrew F. Daughety and
Jennifer F. Reinganum suggested that the opposite was true, and that absence of privacy would also lead to this.
#In the mid-1990s, Varian retook the Chicago Boys approach and added a new externality, stating that the consumer would not always have perfect information on how their own data would be used.
Kenneth C. Laudon developed a model in which individuals own their data and have the ability to sell it as a product. He believed that such a system should not be regulated, to create a free market.
#In the 2000s, researchers worked on
price discrimination (Taylor, 2004), two-sided markets (Cornière, 2011) and marketing strategies (Anderson and de Palma, 2012
). The theories became complex, and showed that the impact of privacy on the economy highly depended on the context.
Data brokers
See also
*
Anonymity
Anonymity describes situations where the acting person's identity is unknown. Anonymity may be created unintentionally through the loss of identifying information due to the passage of time or a destructive event, or intentionally if a person cho ...
* ''
Bundesdatenschutzgesetz''
*
De-identification
*
General Data Protection Regulation
*
Non-personal Data
*
Personal identifier
*
Personal identity
Personal identity is the unique numerical identity of a person over time. Discussions regarding personal identity typically aim to determine the necessary and sufficient conditions under which a person at one time and a person at another time ...
*
Personal Information Agent
*
Protected health information
Protected health information (PHI) under Law of the United States, U.S. law is any information about health status, provision of health care, or payment for health care that is created or collected by a Covered Entity (or a Business Associate of a ...
*
Privacy
Privacy (, ) is the ability of an individual or group to seclude themselves or information about themselves, and thereby express themselves selectively.
The domain of privacy partially overlaps with security, which can include the concepts of a ...
*
Privacy law
*
Privacy laws of the United States
*
Pseudonymity
A pseudonym (; ) or alias () is a fictitious name that a person assumes for a particular purpose, which differs from their original or true meaning (orthonym). This also differs from a new name that entirely or legally replaces an individual's ow ...
*
Obfuscation
Obfuscation is the obscuring of the intended meaning of communication by making the message difficult to understand, usually with confusing and ambiguous language. The obfuscation might be either unintentional or intentional (although intent ...
*
Self-sovereign identity
*
Surveillance
Surveillance is the monitoring of behavior, many activities, or information for the purpose of information gathering, influencing, managing, or directing. This can include observation from a distance by means of electronic equipment, such as ...
Notes
References
External links
Six things you need to know about the new EU privacy frameworkA legal analysis of the new European regulatory framework about data privacy
''Personal and professional information management''Power to the People! Giving Citizens their Personal Data Rights Back– J Cromack
Rethinking Personal Data New Lens Report – World Economic ForumWhy Consent is Different to Marketing Preferences – K Dewar
{{Authority control
Identity documents
Privacy
Personal life
Data security
Data laws
Anonymity