What is a private investigator?
Introduction
Most people never need a private investigator. When they do, something important is usually at stake: a debtor who has moved away, a business deal that needs checking, or a legal case that needs facts rather than guesswork. If you have never hired one, this article explains in plain terms what a private investigator ("PI") does, what the law allows, and how to choose a good one.
What a PI actually does (and doesn't) in the UK
A private investigator is someone who is paid to find, check and record information for a client, using lawful methods. The end result is usually a written report setting out what was found, where it came from and how reliable it is.
A PI is not a police officer. They have no special powers to arrest, search, demand information or see official records closed to the public; legally, they stand in the same position as any member of the public. What they bring is experience and method: knowing where lawful information can be found, how to check it, and how to present it so it can be relied on, including in court.
Common kinds of work
- Tracing. Finding someone you have lost touch with, such as a debtor, a witness or a beneficiary of a will.
- Background checks and due diligence. "Due diligence" simply means checking before you commit. For example, confirming that a potential business partner or supplier is who they say they are, using company records, insolvency notices and published court judgments.
- Evidence gathering. Collecting and documenting facts for civil disputes (disagreements between people or businesses, rather than criminal cases), family matters or employment issues, often working alongside a solicitor.
- Desk-based open-source research. "Open source" means information that is publicly available, such as public registers, news archives and public social media. Done well, each finding is checked, dated and its source recorded.
- Surveillance. Watching and recording a person's activities in public places, for example to test whether an insurance or injury claim is genuine. It must be proportionate (no more intrusive than the purpose needs) and must never become harassment.
The legal framework in plain terms
There is no single "PI law", but several laws matter a great deal:
- Data protection. The UK GDPR and the Data Protection Act 2018 control how personal information is collected, used, stored and deleted.
- Registration with the regulator. Most businesses handling personal information must pay a fee to the UK's data protection regulator, the Information Commission (the ICO), and appear on its public register.
- No licence, but not lawless. Most private investigation work in England and Wales does not require a licence, and the profession is not regulated by a specific statute. The Security Industry Authority (SIA) licenses roles such as door supervisors and security guards; a scheme for investigators was provided for in the Private Security Industry Act 2001 but has never been brought into force.
- Codes of conduct. The Association of British Investigators (ABI) is a professional body that sets standards for its members, including a data protection code of conduct approved by the Information Commission.
- RIPA and the Investigatory Powers Act. The Regulation of Investigatory Powers Act 2000 governs surveillance and the use of covert human intelligence sources by public bodies such as the police and councils, and the Investigatory Powers Act 2016 governs interception and access to communications data. Neither gives private investigators any powers.
- Computer misuse and blagging. Under the Computer Misuse Act 1990, getting into someone's email, phone or online accounts without permission is a crime. Obtaining personal information by deception, known as "pretexting" or "blagging" (for example, pretending to be someone to get their details from a bank), is an offence under the Data Protection Act 2018.
- Harassment. The Protection from Harassment Act 1997 applies to investigators too.
What a PI cannot do
A lawful investigator cannot:
- obtain someone's phone records or listen to their calls or messages;
- access bank accounts or financial records without proper authority;
- search police or other restricted government databases;
- enter private property without permission;
- hack into, or guess passwords for, emails, phones, computers or social media accounts.
If anyone offers these things, walk away. You could be drawn into an offence yourself, and evidence obtained this way may harm your case.
How to choose a PI
- Check registration with the Information Commission. You can search the public register on the Information Commission’s website.
- Look for membership of a recognised professional body, and ask which code of conduct they follow.
- Insist on a written engagement letter setting out what will be done, by when and for how much.
- Expect clear fees, whether hourly, daily or fixed, with any expenses explained in advance.
- Ask about lawful methods. A good investigator will happily explain how they work and why it is lawful.
- Ask for references or an anonymised sample report.
What to expect
First, scoping: a conversation about what you need, why, and whether it can be done lawfully and proportionately. Second, engagement documents: a written agreement recording the purpose and lawful basis of the work. In some tracing cases, the person found may be asked to consent before their details are passed on. Third, the work itself, with updates at agreed points. Finally, a report that sets out findings clearly, separates fact from opinion and records sources. Costs should match what was agreed, with no surprises.
Frequently asked questions
Is it legal to hire a private investigator?
Yes. Hiring a PI is lawful in the UK, provided the work and the methods used are lawful.
Will the person being investigated find out?
Not necessarily, but data protection law gives people rights over their information, sometimes including the right to ask what is held about them. A good investigator will explain how this applies.
Can a PI's report be used in court?
Whether a report can be used as evidence is decided by the court, and depends on how the material was gathered and recorded.
How much does it cost?
It depends on the work. Simple desk-based checks may be a modest fixed fee; complex work costs more. Always get a written quote first.
About Ullr Intelligence
Ullr Intelligence Ltd is registered with the Information Commission and works to UK data protection law and recognised professional good practice. We currently offer desk-based investigation and research only. Our experience includes more than ten years as a surveillance specialist, and our founder holds the SFJ Awards Level 3 Award for Professional Investigators.
If you would like to talk through a matter in confidence, please email info@ullrintelligence.co.uk.