What is PII?
A Guide to Personally Identifiable Information

Data exchange is essential. Businesses cannot process transactions, deliver healthcare, or personalize customer experiences without collecting personal information. From credit card numbers to medical records, personally identifiable information (PII) fuels modern operations.

Understanding how data systems collect, store, and use PII is necessary for preventing security breaches and ensuring compliance with global regulations. But what exactly constitutes PII, and how should organizations safeguard it while maintaining operational efficiency?

This resource provides an in-depth look at PII—its classifications, privacy regulations, and data protection strategies—alongside insights into how Skyflow’s Data Privacy Vault simplifies compliance and security.

What is PII?

Personally identifiable information (PII) refers to any data that can be used to identify a specific individual, either alone – as in a social security number – or when combined with other data – as in a name and birthdate. PII gets collected when someone buys a shirt, registers a car, or visits the doctor. It includes the personal data customers share when interacting with a company, such as name and email address.

Linkable vs. Unlinkable PII

There are two main types of PII: linkable data and unlinkable data.
Linkable data
linkable PII data includes name address email
A direct identifier, such as driver’s license numbers, passport numbers, and Social Security numbers.
Unlinkable data
unlinkable PII data includes gender salary city age
An indirect identifier that requires additional details to identify a person, such as first names, ZIP codes, or demographic information.
On the surface, it may seem like only linkable data is PII. But the classification of data as PII depends on context. Unlinkable data can become linkable when combined with other data. Combining names, ages, and zip codes is often enough to identify specific individuals.

Ultimately, if a piece of data could be used to identify or potentially cause harm to individuals, it’s PII. Even a name and surname alone can (and should) be considered PII.

Take the use of security questions for online verification. The names of cities or colleges are considered unlinkable data. However, cybercriminals can use these pieces of information together with linkable data to bypass security questions and access online resources like bank accounts and health records. Layer in generative AI, which can help stitch together complete pictures, and things get even messier.

Sensitive vs. non-sensitive PII

Sensitive PII is data that, if exposed, could put an individual at risk of harm. Examples include:

  • Driver’s license numbers
  • Medical records
  • Credit card numbers
  • Passport numbers
  • Biometric records

This type of data isn’t publicly available and requires extra security measures due to its potential impact for misuse. For example, criminals can use personal details and bank records to commit identity theft. Some privacy laws apply additional restrictions to certain types of sensitive PII.

Non-sensitive PII is data that, on its own, wouldn’t necessarily harm an individual if exposed. Some examples include:

  • Names
  • Email addresses
  • Phone numbers
  • Birthdates
  • Ethnicities

Unlike sensitive PII, this type of data is often available via public sources like social networking sites, corporate directories, phone books, and public records. Non-sensitive PII has fewer privacy requirements, but companies should still implement data restrictions to prevent unauthorized access. This is because non-sensitive PII can become sensitive PII depending on the context (e.g., names of people who visited a medical facility).

Examples of PII

table comparing linkable unlinkable pii data to sensitive and non-sensitive pii

Who is responsible for protecting PII?

Securing PII is a shared responsibility across multiple stakeholders.

Individuals are responsible for protecting their own PII, which means using strong passwords, securing their devices, and exercising caution in the data they share. They should also monitor their accounts and personal records for any signs of unauthorized access.

At the organizational level, protecting PII is a company-wide effort that involves various roles and responsibilities:

  • Leadership teams define privacy policies and allocate security resources.
  • Managers oversee the implementation of privacy policies and coordinate staff training.
  • Engineering and security teams implement encryption, access controls, and monitoring systems.
  • Compliance teams ensure adherence to regulations such as GDPR and CCPA.
  • Employees must handle PII according to company policies and security best practices.
  • Third-party vendors processing PII must maintain compliance with stringent security requirements.

With these responsibilities in mind, let’s look at why securing PII is so important for an organization.

Why protecting PII matters

PII is incredibly nuanced and not always “black and white.” The risks of ignoring or misclassifying PII are high. With 68% of consumers being somewhat or very concerned about their privacy online, implementing robust data security measures assures customers their PII is secure. Organizations can leverage privacy as a competitive advantage.
68% of global consumers are somewhat or very concerned about their privacy online.  Source: IAPP, Privacy and Consumer Trust Report (2023)

Build and maintain customer trust

Concerns about data privacy affect consumers’ trust in companies. Just look at Apple and Meta’s approach to data security—only one of these companies is building a brand on privacy and trust. Just 18% of US social media users trust Facebook to protect their privacy. Meanwhile, Apple positions itself as a privacy-first company and even makes data security a key selling point in some of its campaigns as shown below.
Apple recognizes that consumers are increasingly concerned about their digital privacy. By highlighting features like cross-site tracking and email privacy protections, the company turns privacy into a compelling value proposition.

Comply with data protection laws

Privacy laws regulate how companies can collect and store PII. Non-compliance can result in massive penalties. Meta was fined a record-breaking $1.3 billion for violating EU privacy laws. By implementing the appropriate data safeguards and adhering to the strictest data privacy laws, businesses can comply with all policies.

Read more: A Brief History of Data Privacy, and What Lies Ahead

Protect against data breaches

Data breaches are devastating for companies that handle PII, especially those in the fintech and healthcare industries. Cybercriminals frequently target these organizations due to the sensitive data they have access to. A cyberattack targeting UnitedHealth Group exposed the personal data of 190 million people, demonstrating the scale and severity of cyber threats to healthcare organizations.

The average cost of a data breach is a record $4.88 million, but the financial losses aren’t the only risk to consider. Data breaches erode trust, which can be challenging to earn back. Proper PII protection can help prevent data breaches and minimize the impact of any given breach.

Read more: Data Breaches: The Problem is PII

Understanding PII laws and regulations worldwide

With growing concerns around how companies collect, use, and store PII, more countries and regions have instituted laws to protect sensitive data. Seventy-five percent of all countries have data privacy laws, which have significant implications for companies with an international presence.

The table below highlights notable countries and their data privacy laws:
table of PII and data privacy laws around the world brazil china indonesia india australia canada europe uk south africa united states

Data protection and privacy in Brazil

The Lei Geral de Proteção de Dados (LGPD) is a legal framework that establishes strict rules for collecting and processing personal information. It has similar provisions to the GDPR, such as requiring explicit consent from data subjects and maintaining transparency about how users’ data is used. Penalties for non-compliance include fines of up to 2% of a company’s revenue in Brazil for the previous fiscal year. The maximum penalty for each violation is R$50 million, the equivalent of about $8.6 million.

Privacy laws in Canada

Canada has several laws and regulatory bodies that protect the privacy of its citizens’ data. Two key pieces of legislation include:

  • Personal Information Protection and Electronic Documents Act (PIPEDA): A federal law that regulates how businesses operating in Canada collect, use, and share personal data. One key aspect of this law is that organizations must obtain an individual’s consent before they can collect or use their information.
  • Québec’s Act to Modernize Legislative Provisions Respecting the Protection of Personal Information (Law 25): Law 25 (previously called Bill 64) strengthens and grants new privacy protections for Quebec residents, including enhanced transparency.

PII regulations in China

The Personal Information Protection Law (PIPL) is an extensive data privacy law in China that protects the information of its citizens. It applies to organizations that collect, store, and use the personal data of individuals in China. China’s data regulatory regime also includes a Cyber Security Law (CSL) with enhanced protections for “important data.”

Read more: China Data Residency: A Guide to Compliance with PIPL & CSL

PII privacy regulations in the EU/UK

The General Data Protection Regulation (GDPR) is Europe’s main privacy and security law. It contains 99 articles across 11 chapters describing the data rights granted to EU/UK residents. The risks of non-compliance include fines of up to €20 million or 4% of global annual revenue.

The GDPR’s definition of PII, or “personal data”, is the most comprehensive among PII regulations. Personal data includes:

  • Names
  • Addresses
  • Internet Protocol (IP) addresses
  • Mobile device IDs
  • Cookie identifier

Protection requirements are another key distinction. Directly identifiable data, which can identify an individual without additional information (e.g., full names, passport numbers), is protected under the GDPR. However, the GDPR mandates the protection of all data regardless of its sensitivity level, meaning sensitive and non-sensitive PII are both protected.

Read more: GDPR Compliance Made Easy

Personal data protection in India

India’s Digital Personal Data Protection Act (DPDP) is one of the latest privacy laws passed in Asia. It regulates and protects the collection and processing of information on Indian residents. The penalties for non-compliance can be steep—up to ₹250, the equivalent of $30 million.

Read more: India’s DPDP Rules 2025: Critical Highlights & How to Comply

Data protection laws in the United States (US)

The United States has multiple state laws and one federal law for PII. These include:

  • California Consumer Privacy Act (CCPA): Gives California residents certain data rights, such as the right to access their data and opt out of data collection.
  • Virginia Consumer Data Protection Act (VCDPA): Provides Virginia residents with the right to access their personal data and opt out of its sale.
  • Colorado Privacy Act (CPA): Protects Colorado residents’ personal data and gives them the right to opt out of targeted advertising.
  • Utah Consumer Privacy Act (UCPA): Gives Utah residents the right to know what personal data businesses collect about them.
  • Privacy Act (1974): A federal law that governs the collection and use of data that federal agencies maintain about certain individuals.

PII laws in other regions

Other notable privacy laws include:

  • Australia’s Australian Privacy Principles (APP)
  • Indonesia’s Personal Data Protection (PDP)
  • Japan’s Act on Protection of Personal Information (APPI)
  • Singapore’s Personal Data Protection Act (PDPA)
  • South Africa’s Protection of Personal Information Act (POPIA)

Read more: How to Achieve Global Data Privacy Compliance

Compliance with privacy regulations is critical for businesses managing sensitive customer data. In addition to regional privacy laws, some industries have their own unique requirements for handling personal data.

Industry-specific PII protection regulations

Certain US industries have their own data privacy regulations. Each has different requirements for how organizations should collect, store, and handle PII

Healthcare institutions

The Health Insurance Portability and Accountability Act (HIPAA) was established to set comprehensive regulatory standards for healthcare organizations to safeguard protected health information (PHI). Non-compliance with HIPAA can result in heavy penalties. One medical center was hit with a $4.75 million penalty after an investigation revealed an employee unlawfully accessed and sold the PHI of over 12,000 patients.

Companies ranging from direct-to-consumer healthcare providers to healthcare technology solutions must ensure the privacy and security of any PHI they collect.

Read more: How to Guide: Four PII Protection Best Practices in Healthcare

Financial services

The Gramm-Leach-Bliley Act (GLBA) is a financial privacy law that requires financial institutions to safeguard and ensure the confidentiality of their customers’ financial data. Penalties for non-compliance include ​​fines of up to $100,000 for each violation or imprisonment for up to five years.

In this case, “financial institutions” refer to more than just banks—the law also applies to mortgage brokers, tax preparers, and fintech companies. The Federal Trade Commission (FTC) recently strengthened a key component of GLBA called the Safeguards Rule. It requires financial institutions to regularly test the effectiveness of their data security safeguards.

Read more: Avoiding the Five Cardinal Sins of Fintech Data Privacy

Payment processing

The Payment Card Industry Data Security Standard (PCI DSS) sets standards for companies that store and process cardholder data. With the exception of cash-based businesses, companies must adhere to the PCI DSS. Penalties for non-compliance can range from $5,000 to $100,000 per month and may result in Termination of Merchant Account or Card Network Blacklisting.

Read more: A Guide to the 4 Levels of PCI Compliance

These are just a few PII regulations that apply to specific industries. As privacy laws continue to change and new legislation passes, staying up to date with compliance requirements is critical.

How PII data proliferates in internal systems

Organizations often struggle to protect PII because they don’t realize the extent to which the data has proliferated throughout their systems. Understanding how data proliferates is essential to securing and governing access.

For example, a company using a CRM system might copy customer data into a data warehouse for analysis. The development team could then move this data into a testing environment, while sales and product teams share it across systems to streamline workflows. In some cases, employees may even inadvertently expose data to AI models, as Samsung discovered with ChatGPT.

Here’s what sensitive data sprawl can look like in traditional infrastructures:

architecture diagram of sensitive PII data spreading throughout a data infrastructure and apps

Even if the data is secure in its original location, replication across multiple systems introduces significant security risks and leads to sensitive data sprawl. When PII is duplicated and scattered across systems, it creates new access points for cybercriminals and complicates compliance with privacy laws like GDPR, which require the deletion of personal data on request.

Read more: What Is Sensitive Data Sprawl and How Can You Prevent It?

To address these challenges and minimize the risks of sensitive data sprawl, organizations need a focused approach to PII data security.

PII data security: How to protect and safeguard personal data

Data is often called “the new oil” for its value in unlocking insights. But it can also become a massive liability when it’s not handled correctly.

Here’s how to protect and safeguard PII data:

1. Minimize data collection and track its use

Follow the principle of “data minimization” by only collecting and retaining the PII needed for specific tasks. A retailer, for example, should only collect the data needed to process transactions, such as names and addresses.

Additionally, audit logs must be maintained to track and monitor how sensitive data is accessed and used. Monitor all data access activities regularly to detect malicious misuse or potential security incidents.

2. Use strong encryption at rest and in transit

Unprotected data is an easy target for cybercriminals. Consider the 2017 Equifax data breach, one of the largest breaches involving over 143 million people’s personal data. Attackers successfully located and transferred unencrypted PII out of the company’s network. In this case, stronger encryption protocols could have reduced the impact of the breach.

Encryption scrambles readable text into ciphertext, rendering it unreadable without the decryption key. Implement strong encryption for PII when it’s stored (at rest) and when it’s being transmitted (in transit) to protect against unauthorized access.

A data privacy vault with polymorphic encryption allows encrypted data to remain easily usable without first being decrypted.

Read more: What is Polymorphic Encryption?

3. Enforce strong passwords and require multifactor authentication (MFA)

In 2021, a security researcher discovered that a non-password-protected database owned by DreamHost exposed 814 million records. The incident is a good reminder that organizations need to enforce strong passwords. Of course, even passwords can be compromised through breaches or phishing attacks—which is why MFA has become the done thing.

4. Keep PII and sensitive data out of logs

Logging PII with certain application events can give engineering teams insights into their systems, helping them identify issues and optimize performance. However, doing so presents security and compliance risks.

Avoid logging PII in its original form to prevent sensitive data from falling into the wrong hands. Tokenization swaps sensitive data with randomized strings, a process that can only be reversed by users authorized to access the tokenization system. This allows teams to write sensitive data safely to a log without risking exposure.

Read more: Keep Sensitive Data Out of Your Logs: 9 Best Practices

architecture diagram of how to keep sensitive PII data out of other applications using tokens redaction encryption

5. Govern data access in your tech stack

In 2024, 68% of data breaches involved human error, such as falling victim to social engineering attacks. Human error also includes privilege misuse, which occurs when users abuse their access privileges to gain unauthorized access to sensitive data. With fine-grained access control, companies can restrict data access at granular levels and ensure certain roles only see the minimum necessary data for their jobs.

Read more: What is Fine-Grained Access Control for Sensitive Data?

6. Protect and govern data privacy vault

Sensitive PII gets copied and replicated across various applications and services in traditional system infrastructures, making it difficult to secure PII and meet compliance requirements.

A data privacy vault addresses these challenges by isolating sensitive data from other systems. Solutions like Skyflow’s Data Privacy Vault provide a centralized, secure vault for sensitive data and maintain its usability for applications and analytics.

Read more: What Is a Data Privacy Vault?

How a data privacy vault protects PII

Without a data protection strategy, organizations risk exposing customers’ PII and incurring penalties for non-compliance.

A data privacy vault secures customer data and enables compliance with privacy laws. It eliminates sensitive data sprawl by isolating and securing PII at its source.

architecture diagram of a PII personal data privacy vault data warehouse analytics

Unlike fragmented security tools, a data privacy vault should provide:

  • Fine-grained access control—Restricts who can see what data.
  • Zero-trust architecture—Ensures security across multi-cloud environments.
  • Data residency solutions—Comply with region-specific regulations.
  • LLM-compatible security—Protect PII used in AI models without decrypting it.

Whether companies operate in fintech, healthcare, or retail, a data privacy vault offers a comprehensive solution for protecting sensitive data and achieving global compliance.

Frequently Asked Questions About PII

What violates PII?

Common PII violations include unauthorized access or disclosure of PII, improper storage, and failure to obtain consent.

What is an example of misuse of personal data?

Examples of misusing personal data include sharing PII without consent, selling data to third parties without permission, failing to properly secure data, as well as using information in a manner inconsistent with its original purpose (see: Twitter uses your 2fa number for advertising).

How do you identify PII data?

PII is often difficult to identify, but it can be linkable or unlinkable data. If it can be used to identify an individual, it’s PII. Even unlinkable data, like names and genders, can be PII.

What are the three main types of data classification?

Common data classification categories include:

  • Public: Freely available information
  • Internal: Business data requiring basic protections
  • Confidential: Sensitive data requiring stricter controls

Classifying data can help companies implement the proper controls.

Enhance PII data security

Collecting data can unlock valuable insights. However, companies must tread carefully when collecting and processing personal data, especially given the scope of privacy laws like the GDPR and CCPA. PII violations can result in massive penalties and erode customer trust. A data privacy vault enables organizations to secure sensitive data, comply with regulations, and maintain business agility.

Learn how you can build a secure and best-in-class infrastructure that safeguards PII and simplifies compliance.