Personal Identifiable Information (PII)

Personally Identifiable Information (PII)

Personally Identifiable Information (PII) is information that can identify an individual directly or indirectly. Examples include a person’s name, email address, phone number, government-issued identification number, or combinations of data that can be used to identify someone.

Organizations collect PII across websites, applications, cloud environments, databases, employee systems, and business platforms. Protecting this information is an important part of cybersecurity, privacy, compliance, and data protection.

What is Personally Identifiable Information (PII)?

Personally Identifiable Information (PII) refers to information that can be used to identify, contact, distinguish, or reasonably link to a specific individual.

PII can identify someone directly, such as through a passport number, or indirectly when multiple pieces of information are combined.

The exact definition of PII varies by jurisdiction, regulation, and organizational context. For example, U.S. security guidance commonly uses the term PII, while regulations such as the GDPR generally use the broader term personal data.

Examples of PII

PII can include many different types of information.

Direct Identifiers

Direct identifiers can identify an individual by themselves or with little additional information.

Examples include:

• Full name
• Passport number
• National identification number
• Driver's license number
• Social Security number
• Personal email address
• Personal phone number
• Biometric identifiers
• Unique account identifiers

Indirect Identifiers

Indirect identifiers may not identify someone independently but can contribute to identification when combined with other information.

Examples include:

• Date of birth
• Age
• ZIP or postal code
• Geographic information
• Employment information
• Device identifiers
• IP addresses, depending on context
• Online identifiers
• Demographic information

Sensitive PII

Sensitive PII generally refers to information that could create greater privacy, security, or harm risks if exposed or misused.

Examples can include:

• Government identification numbers
• Financial account information
• Authentication credentials
• Biometric information
• Medical information
• Highly sensitive personal attributes
• Precise location information

Whether a specific data element is legally classified as sensitive depends on the applicable jurisdiction and regulation.

Types of PII

PII can be grouped into several categories:

PII vs Personal Data

PII and personal data are closely related concepts, but they are not always interchangeable.

PII is commonly used in U.S. information-security and privacy contexts to describe information that can identify an individual.

Personal data is the broader legal concept used by regulations such as the GDPR and can include information relating to an identifiable person even when the information does not directly identify them.

The applicable definition depends on the law, jurisdiction, and context.

PII vs Personal Information

The terms PII and personal information are often used similarly in cybersecurity discussions, but their legal meanings can differ.

For example, U.S. privacy laws may define "personal information" or similar terms according to specific statutory criteria. Organizations should therefore use the applicable legal definition when determining compliance requirements.

PII vs PHI

PII and Protected Health Information (PHI) overlap but are not identical.

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Some information can qualify as both PII and PHI.

How Does PII Protection Work?

PII protection involves identifying personal information, determining its sensitivity, controlling access to it, monitoring its use, and securely disposing of it when it is no longer required.

A typical PII protection lifecycle includes:

Discover → Classify → Collect → Store → Use → Monitor → Share → Retain → Dispose

Organizations should apply appropriate security controls throughout this lifecycle.

PII Data Lifecycle

1. PII Discovery

Organizations identify where PII exists across:

• Databases
• Applications
• Cloud storage
• SaaS platforms
• Endpoints
• File shares
• Email systems
• Data warehouses
• Logs

2. PII Classification

Data is categorized according to sensitivity, regulatory requirements, business importance, and risk.

3. PII Collection

Organizations should collect only the information necessary for a legitimate business purpose.

4. PII Storage

PII should be protected using appropriate access controls, encryption, monitoring, and secure storage practices.

5. PII Usage and Sharing

Access and sharing should be limited according to business requirements and applicable privacy obligations.

6. PII Retention

Organizations should establish appropriate retention periods and avoid retaining unnecessary information indefinitely.

7. Secure Disposal

PII should be securely deleted, destroyed, or otherwise rendered unusable when it is no longer required.

How Organizations Protect PII

Encryption

Encryption protects PII while it is stored and transmitted.

Access Control

Access should be limited to authorized users and systems.

Multi-Factor Authentication

MFA reduces the risk of unauthorized account access.

Data Masking

Masking hides portions of sensitive information from users who do not need to see the complete value.

Tokenization

Tokenization replaces sensitive information with tokens that can be used instead of the original data.

Data Loss Prevention

DLP technologies can identify and help prevent unauthorized transmission or exposure of sensitive information.

Data Discovery and Classification

Organizations need visibility into where PII exists and how sensitive information is being handled.

Security Monitoring

Monitoring and logging can help detect suspicious access and potential data exposure.

PII Security Controls

A comprehensive PII security program can include:

• IAM
• RBAC ‍
• MFA
• Encryption
• DLP
• Data classification
• Data discovery
• Tokenization
• Data masking
• Database security
• Endpoint protection
• Network security
• SIEM
• ‍Vulnerability management
• Security testing
• Audit logging
• Incident response

PII Classification

PII classification helps organizations determine which information requires additional security controls.

A practical classification model can include:

Public → Internal → Confidential → Sensitive/Restricted

The exact classification scheme should be aligned with the organization's security policies and regulatory requirements.

Where is PII Stored?

PII may exist across virtually every layer of an organization's technology environment.

Common locations include:

• Customer databases
• HR systems
• CRM platforms
• Cloud storage
• SaaS applications
• Email systems
• End-user devices
• Mobile applications
• Web applications
• Data warehouses
• Backup systems
• Logs and monitoring platforms
• Development and testing environments

Development and test environments can create additional exposure when production PII is copied without appropriate controls.

PII and Data Loss Prevention (DLP)

DLP helps organizations identify, monitor, and control sensitive information.

DLP solutions can detect patterns associated with PII and help prevent unauthorized activities such as:

• Emailing sensitive information externally
• Uploading PII to unauthorized cloud services
• Copying sensitive files to removable media
• Sharing sensitive information through unapproved applications

PII Risk Assessment

A PII risk assessment helps organizations identify:

• What PII they collect
• Where it is stored
• Who can access it
• How it is processed
• Where it is transferred
• How long it is retained
• What security controls protect it
• What could happen if it were compromised

Organizations can then prioritize controls according to risk.

PII Inventory

A PII inventory documents the personal information an organization collects and processes.

A useful inventory can capture:

PII Best Practices

Organizations should:

1. Discover where PII is stored and processed.
2. Maintain an accurate PII inventory.
3. Collect only necessary information.
4. Classify PII according to sensitivity.
5. Apply least-privilege access.
6. Use MFA for privileged and sensitive access.
7. Encrypt sensitive data.
8. Monitor access to PII.
9. Use DLP where appropriate.
10. Protect PII in development and test environments.
11. Establish retention and secure-disposal policies.
12. Regularly assess vulnerabilities and security configurations.
13. Train employees on handling sensitive information.
14. Maintain an incident-response process for potential data exposure.
15. Review third-party access to PII.

Risks of Exposed PII

Poor PII protection can contribute to:

• Identity theft
• Credential attacks ‍
• Social engineering
• Financial fraud
• Account takeover
• Targeted phishing
• Privacy violations
• Regulatory exposure
• Reputational damage

The actual impact depends on the type and amount of information exposed, the affected individuals, and the circumstances of the incident.

PII Security Checklist

Use this checklist to evaluate basic PII protection:

• Identify where PII is stored.
• Maintain a PII inventory.
• Classify sensitive information.
• Apply least-privilege access.
• Enable MFA.
• Encrypt sensitive data.
• Monitor access and activity.
• Deploy DLP where appropriate.
• Protect PII in cloud environments.
• Secure applications and APIs.
• Establish retention periods.
• Securely dispose of unnecessary data.
• Review third-party access.
• Test incident-response procedures.
• Regularly assess vulnerabilities.

FAQs

Q1. What is PII?

PII stands for Personally Identifiable Information and generally refers to information that can identify an individual directly or indirectly.

Q2. What are common examples of PII?

Common examples include names, email addresses, phone numbers, government identification numbers, addresses, financial information, and certain online or device identifiers.

Q3. Is an IP address considered PII?

An IP address may be treated as identifying or personal information depending on the applicable legal framework and context.

Q4. Is an email address PII?

An individual's email address can generally be identifying information, particularly when it is associated with a specific person.

Q5. Is a phone number PII?

A phone number associated with an individual can be considered identifying or personal information depending on the applicable framework.

Q6. Are cookies PII?

Cookies are not inherently PII, but cookie identifiers and related data can create privacy implications when they are linked to an identifiable individual.

Q7. What is the difference between PII and personal data?

PII is commonly used to describe identifying information, while personal data is a broader legal concept used by regulations such as the GDPR. The exact scope depends on the applicable framework.

Q8. What is the difference between PII and PHI?

PII is a broad concept covering identifying information. PHI specifically concerns individually identifiable health information in applicable healthcare contexts.

Q9. What is sensitive PII?

Sensitive PII refers to identifying information that can create greater privacy or security risks if exposed or misused.

Q10. How can organizations protect PII?

Organizations can protect PII using access controls, MFA, encryption, DLP, data classification, monitoring, secure application practices, vulnerability management, and secure disposal.

Q11. Can PII be stored in the cloud?

Yes. PII can be stored and processed in cloud environments, but organizations should apply appropriate identity, access, encryption, monitoring, and data-protection controls.

Q12. Why is PII important in cybersecurity?

Protecting PII helps reduce the risk of unauthorized disclosure, identity theft, fraud, account compromise, and other consequences associated with personal information exposure.