What is personally identifiable information?

Definition

Personally identifiable information is a general term for data that can identify an individual: names, addresses, phone numbers, emails, dates of birth, government ID numbers and account numbers. Some items identify a person on their own; others do when combined.

It's a privacy and security term rather than a single legal definition. For advisers and broker-dealers, the legal term that usually matters more is "nonpublic personal information" under Regulation S-P.

Why it matters for advisors

PII is what you're trying to keep out of unapproved AI tools. An AI policy that says "no client data in personal AI accounts" is really about PII and NPI.

It also shows up in vendor contracts and security questionnaires, so it helps to know that vendors may use PII in a narrower or broader sense than your firm does.

When a vendor says it removes PII before processing, ask what it removes and how. Automated redaction catches obvious items like Social Security numbers but can miss names in context, family details or account nicknames.

Example

Before asking a general assistant to help structure a client letter, an advisor replaces the client's name, address and account numbers with placeholders.

Watch out for

Removing the name isn't always enough. A rare job title, a small town and an exact account balance can identify someone together.