Can I Hire a Private Investigator to Follow Someone in the UK?

Updated 6 September 2026 by K3K Investigations

Yes. Hiring a private investigator to follow someone is lawful in the UK when it is done for a legitimate purpose, in public, proportionately and without harassment, and it is the basis of most matrimonial, insurance and workplace evidence that reaches a court. It is unlawful, and refused by any reputable agency, when the purpose is to intimidate, to pursue someone who has cut contact, or to breach a court order. This guide explains where the lines sit, what a surveillance operation actually involves, what it costs by the day, and how to tell an agency that will keep you on the right side of the law from one that will not.

The UK still has no statutory licence for private investigators, which surprises most clients. What governs following someone is therefore the general law: harassment, data protection, trespass, privacy and the rules of evidence. A professional agency knows those rules the way a driver knows the road, and the practical result is that lawful surveillance is routine while unlawful surveillance is a liability for the client as much as the investigator.

What the law allows

Observation in public is lawful. A person walking down a street, sitting in a café, driving on a road or entering a building from a public pavement has no reasonable expectation that nobody will see them. Covert surveillance records what any member of the public could have witnessed, only systematically and with timestamps.

Data protection applies. Following someone and recording them is processing their personal data. A professional agency does it under a documented lawful basis, usually a legitimate interest, weighed against the subject's rights, and K3K Investigations Ltd is registered with the Information Commissioner's Office for exactly that reason. Our guide on whether it is legal to hire a private investigator covers the framework in more detail.

Harassment is the boundary. The Protection from Harassment Act 1997 criminalises a course of conduct that causes alarm or distress. Covert, proportionate surveillance that the subject never notices, conducted for a legitimate aim, is not harassment. Repeated overt following, confrontation, or surveillance whose real purpose is to frighten someone plainly is, and the client who commissioned it shares the exposure.

Private property is off limits. Investigators do not enter homes, gardens or private premises without permission, do not place cameras inside private spaces, and do not intercept calls or messages. Anyone who offers to is offering to commit an offence and to hand you evidence a court will throw out.

RIPA is not your problem. Clients often ask whether they need authorisation under the Regulation of Investigatory Powers Act. That regime governs public bodies. Private surveillance is governed by the law above, not by RIPA, though the proportionality principle it embodies is a good habit for anyone.

Who hires an investigator to follow someone, and why

Partners who suspect infidelity and need certainty before a decision that will reshape their lives. Evidence gathered lawfully is accepted in family proceedings, and just as often the surveillance clears the person suspected.
Employers dealing with sickness-absence abuse, an employee working a second job while signed off, theft, or someone breaching a restrictive covenant on the way to a competitor. Tribunals accept proportionate covert surveillance where a reasonable employer would have had grounds for it.
Insurers and defendant solicitors testing whether a claimed injury matches a claimant's actual activity. This is the most established use of surveillance evidence in the English courts.
Landlords with a tenant suspected of subletting or not living at the property.
Solicitors who need a witness located, a subject's pattern of life established, or a person served with papers who is evading service.

What a surveillance operation actually looks like

An instruction begins with a free conversation about what you need to know, what evidence would settle it, and whether surveillance is the proportionate route. If it is, we quote a fixed price in writing. Before deployment the team studies the ground: addresses, routes, transport, the places the subject is likely to go. Our own OSINT platform maps the CCTV, road layout and public infrastructure around a location so operatives arrive knowing the area.

On the day, one to three trained operatives work on foot and by vehicle, handing the subject between them so that no single face or car is seen twice. Everything relevant is recorded on timestamped video and in a contemporaneous log. Where a vehicle's movements matter more than a person's, a lawfully deployed tracker run on our K3K Intelligence platform can replace a second vehicle, subject to the assessment described in our guide to GPS tracker law.

You receive a written report with the footage: what happened, when, where and how it was observed, prepared so that a solicitor can use it and a court can follow it. Our anonymised case story from South London shows an operation from first call to final report.

What it costs

Surveillance is priced per operative per day, and at K3K that is £500 to £1,200 per operative-day depending on the team size, the vehicles and the hours involved, quoted fixed before work begins. A typical matrimonial instruction runs to two or three days chosen for the moments that matter rather than a fortnight of watching a front door; a workplace or insurance instruction is usually similar. Our full guide to private investigator costs explains the day-rate arithmetic and the red flags in cheap quotes.

The instructions we refuse

We refuse to follow an ex-partner who has ended contact, anyone protected by a restraining, non-molestation or occupation order, or anyone where the client's account of why does not hold together. We look hard at instructions involving children and accept only proportionate welfare concerns from someone with parental responsibility. We decline surveillance whose purpose is to confront, expose or intimidate rather than to establish a fact. These refusals are not caution for its own sake: they are what keeps the surveillance we do lawful, and they are the difference between evidence and a harassment complaint with your name on it.

Frequently asked questions

Is it legal to have someone followed in the UK?

Yes, when it is done for a legitimate purpose, in public, proportionately and without harassment. Surveillance of an ex-partner who has cut contact, of anyone protected by a court order, or for the purpose of intimidation is unlawful, and a reputable agency will refuse it.

Can I hire a private investigator to follow my husband or wife?

Yes. Matrimonial surveillance is lawful and among the most common instructions UK investigators take. The evidence is accepted in family proceedings, and the outcome is honest either way: the surveillance confirms the suspicion or, just as often, clears the person suspected.

Can my employer have me followed?

An employer can commission proportionate covert surveillance where it has reasonable grounds, for example credible evidence that an employee signed off sick is working elsewhere. Tribunals expect the surveillance to be necessary, targeted and documented, and evidence gathered that way is regularly accepted.

How much does it cost to have someone followed for a day?

K3K quotes surveillance at £500 to £1,200 per operative per day depending on team size, vehicles and hours, fixed in writing before work starts. Most instructions need two or three carefully chosen days rather than continuous coverage.

Will the person know they are being followed?

Professional surveillance is designed to be undetected: trained operatives, rotated vehicles and faces, and a stop-and-withdraw rule if there is any sign of compromise. Being noticed ends the operation and risks a harassment complaint, which is why experienced teams withdraw rather than press on.

Can a private investigator follow someone abroad?

Yes. K3K runs surveillance overseas through vetted partner agencies under our direction, with the same evidential standards and a fixed quote agreed in advance.

Need to know what is really happening? Speak to a senior investigator in confidence — free, no obligation, and honest about whether surveillance is the right tool. Call 020 3343 7007 (24 hours) or book a call.