On the 1st September 2026 I began posting to TikTok @d74pi and the one question I keep getting is ‘can a private investigator legally follow someone in the UK?’ and the answer is yes. Absolutely. I have been doing this for 10 years now and never had a run in with the police or any legal trouble as my team and I at Delta 74 Private Investigations do it all legally.
Is it legal for a private investigator to follow someone?
Yes it is completely legal but we have to establish a lawful basis and set a lawful objective to the surveillance to be able to show that surveillance will be the ONLY way to achieve the objective.
We need to show;
- The purpose of the investigation
- How proportionate it will be – things like how long we carry out surveillance for etc
- Exactly what is to be achieved which then sets when it will end
- What information and evidence is to be gained and how
- Then how the evidence is; handled, stored, who touches it and for how long
Most of this is done and covered under the Lawful Basis of our Data Protection Impact Assessment (DPIA) and Legitimate Interests Assessment (LIA).
Legal surveillance needs to be for legal reasons. Following someone to find out if they are going to the gym would not be a enough of a reason.
Can a PI follow someone without them knowing?
The very essence of surveillance by a PI is that it is covert. For our work not to be deemed as stalking or harassment, surveillance needs to be covert so the subject of investigation does not they are being followed in that they then don’t feel; alarmed, distressed, stalked or harassed.
As soon as someone knows they are being followed that person will feel those feelings of harassment and be able to call for police help to remove that threat.
The minute a PI is discovered by the subject of investigation to be following them, the PI must cease the surveillance and treat the investigation as compromised.
The other caveat to the subject of investigation not knowing is that the surveillance will then show a true reflection of what that person was doing when they thought no-one was watching. This is why the surveillance was able to be lawful as it was the ONLY way to gather that evidence.
Where can PIs carry out surveillance?
Private investigators can only follow people in public spaces. This is the same for gathering evidence. This falls under the Human Rights Laws – Article 8 Right to Family and Private Life.
If you are in a place that you would deem you have made to be private then PI’s are not to follow or record you.
Places include private residence’s such as;
- Your home or your family’s homes. Including back gardens.
- Hospitals and surgeries. These are protected spaces where you would expect a right to privacy.
- Within your hotel room. As part of your stay you have paid for privacy within the room.
Now on the topic of paying for entry. This does not mean that a place is private because you paid for entry. For example a theme park would not be considered a private place just because you paid for entry. We can follow to places like a theme park and record you. Another location considered private is a school, the outer exterior of a school prior to picking up children is ok when parents are waiting for entry outside the gate but once the children’s home time occurs then it becomes a protected space.
Can a PI film someone in public?
This is the only place we can film and gain evidence of someone.
The grey area is where people think public areas stop against where it actually stops.
The best way to think of this is Google Street View. If Google Street can go there and produces images then we can too. If you are in your front garden where passers-by could see you then we are able to film you too. The next bit is the hue grey area!
Can a PI film into windows?
This is something Google have fallen short on in past years when they captured the picture of the man on his bed playing *ahem* alone but his curtains were wide open.
For us Human Rights Act Article 8 – Right to Private and Family Life dictates here. If someone enters a private address or their home then they are under that right not able to be filmed.
Where it gets confusing is if someone is in the window looking out they can be seen by the public from the public domain so technically they are fair game as they have made no effort to protect their right.
For us as Private Investigators, it all comes down to proportionality around the objective and the level of intrusion we can reach. If someone is involved with a high fraud case and are exercising in there front open window then it would be proportionate to film them opposed to someone simply sitting and having a cup of tea as it gains no evidence of use.
Does RIPA 2000 apply?
In short, no.
RIPA 2000 is The Regulation of Investigatory Powers Act which determines and regulates how Public Authorities carry out covert surveillance and investigations.
It can apply to Private Investigators if we work and are employed by a Public Authority or Government Department.
This applies to the below and some others;
- MI5, MI6 and GCHQ
- The Police
- Local Councils and Local Authorities
- HMRC (who do have their own surveillance teams)
- The Financial Conduct Authority (FCA)
- The Environment Agency
The Unofficial Regulator - The ICO
At the moment the Private Investigation industry in the UK is unlicenced and unregulated however, The Information Commissioner’s Office are the main ones who can hold us to account.
They have in the past issued sizeable fines for breaches to Private Investigators and continue to be the main overseer of how we do things as almost everything we do is governed by Data Protection Laws.
If you have a grievance with a PI you’re best bet is to get the ICO involved.
Can Surveillance evidence be used in court?
After a PI has followed someone we will then usually (not always) produce a report and handle the evidence in accordance with the law.
That then serves as the product you have purchased and it absolutely can be used in court and is often used in court today. Especially in insurance fraud cases where someone involved in an accident or incident exaggerates their claim and the surveillance footage then shows them displaying a better lifestyle than they have claimed.
So long as the surveillance was granted and carried out lawfully and the subject not aware, then the evidence gained from the public space is entirely legal.
Finishing up
This has been one of my longest posts yet but with starting my TikTok page this is one the main questions I have been asked; Can a Private Investigator Legally Follow Someone?
The simple answer is Yes! As always, thanks for reading! Dan
