Is It Legal to Hire a Private Investigator to Follow Someone?

Published August 14, 2026

If you suspect a cheating spouse, want to locate a missing person, or need to verify someone's activities for a legal matter, you may be wondering: is it actually legal to hire a private investigator to follow someone? The short answer is yes — but with important boundaries. What a PI can legally do depends on where you are, who is being followed, and how the surveillance is conducted. Getting those boundaries wrong can expose both you and the investigator to serious legal consequences.

The Legal Foundation: Surveillance in Public vs. Private Spaces

The clearest legal principle governing physical surveillance is the concept of a reasonable expectation of privacy. When someone is in a public place — walking down a street, sitting in a park, entering a business — they generally have no reasonable expectation that their movements are private. A licensed private investigator can legally observe and document activities that are visible from public spaces without a warrant or special permission.

However, that protection disappears the moment surveillance crosses into private spaces. A PI cannot legally:

• Trespass on private property to observe or photograph a subject
• Wiretap phone calls or intercept electronic communications without consent, which is a federal crime under the Electronic Communications Privacy Act
• Hack into email, social media, or other digital accounts
• Impersonate a law enforcement officer or use false pretenses that cross into fraud
• Place a GPS tracker on a vehicle they do not own without authorization — laws on this vary significantly by state
• Access protected records such as financial accounts, medical files, or phone records through unauthorized means

Any investigator who offers to do these things is operating outside the law. A reputable, licensed PI will tell you clearly what they can and cannot do.

Licensing Requirements Vary by State

Private investigators are licensed at the state level, and the rules differ considerably from one state to the next. Some states have strict licensing requirements including background checks, training hours, and examinations. Others have more limited oversight. Before hiring anyone, you should verify that the investigator holds a current, valid license in the state where the work will be performed.

In Texas, for example, private investigators must be licensed through the Texas Department of Licensing and Regulation (TDLR). Texas has detailed statutes governing what investigators may and may not do, and operating without a license is a criminal offense. If you are in Texas or hiring someone to conduct surveillance there, confirming licensure with the relevant state authority is an important first step. You can look up licensing agencies and verify credentials through USA.gov's directory of government services and licensing resources.

Who Can Legally Hire a PI to Follow Someone?

Generally speaking, any private individual or business can retain a licensed private investigator for a legitimate purpose. Common lawful reasons people hire PIs to conduct surveillance include:

• Suspected infidelity in a marriage or domestic partnership
• Verifying a subject's whereabouts for a child custody dispute
• Insurance or workers' compensation fraud investigations
• Locating a person who owes a debt or has skipped out on a legal obligation
• Gathering evidence for a civil lawsuit
• Corporate due diligence and employee misconduct investigations

The key word is legitimate. Hiring a PI to harass someone, stalk an ex-partner, or gather information for an illegal purpose is not protected by law — and could make you criminally liable as well. If your situation involves a legal matter such as divorce, custody, or litigation, consult a licensed attorney before you hire an investigator. An attorney can help ensure that any evidence gathered will be useful and admissible, and can advise you on your specific legal rights. Nolo's legal information library is a helpful starting point for understanding your general rights in civil and family law matters.

What About Background Checks and Records?

Following someone physically is just one tool investigators use. Many clients also want a PI to research a subject's background. Here too, legal limits apply. Federal law — particularly the Fair Credit Reporting Act (FCRA) — governs how consumer information can be collected and used. If a background check is being used for employment, housing, or credit decisions, specific legal rules apply to both the investigator and the person who hired them. The Federal Trade Commission publishes guidance on background checks and consumer rights that is worth reading if your request involves personal records.

A licensed PI can access publicly available records, court documents, property records, and other open sources lawfully. What they cannot do is access protected databases — such as certain law enforcement systems, private financial records, or medical information — without proper authorization.

Questions to Ask Before You Hire a PI

To protect yourself legally and get the best results, ask any investigator you are considering these questions before signing a contract:

1. Are you licensed in the state where the investigation will take place? Ask to see the license number and verify it independently.
2. What methods will you use, and are they all legal in this jurisdiction? A professional will answer this clearly and specifically.
3. What is your experience with cases like mine? Surveillance for a custody dispute differs from a fraud investigation.
4. How will you document and deliver evidence? Understand the format — written reports, photographs, video — and how it will hold up if needed in court.
5. What are your fees and how are they structured? Hourly rates, retainers, and expense reimbursements should all be spelled out in writing.
6. What will you not do? A trustworthy investigator will be upfront about legal limitations without you having to ask.

The Bottom Line

Hiring a licensed private investigator to follow someone is legal when conducted properly, for a legitimate purpose, using lawful methods. The investigator's job is to gather information — not to guarantee a specific outcome or take actions that cross legal or ethical lines. Surveillance conducted in public spaces, documented professionally, and handed over to a client or their attorney is a well-established and lawful practice. What matters is that both you and the PI stay within the boundaries the law sets.

For a deeper look at how privacy law applies in surveillance contexts, the Legal Information Institute at Cornell Law School offers plain-language explanations of relevant federal statutes. And if your matter could end up in court, speaking with a licensed attorney in your state before proceeding is always a wise move.

If you are ready to explore your options, Find A Local PI can connect you with a licensed private investigator in your area at no charge and with no obligation. Simply use our site to submit your inquiry, and a qualified professional will be in touch to discuss what may be possible in your situation.