Is My Tenant Subletting My Property Without Permission?

October 14, 2023 - Reading time: 5 minutes
Updated on: April 6, 2025

If you’re a landlord, knowing who lives in your property is more than just a formality — it’s a necessity. But what happens if your tenant is subletting the property without telling you? Whether it’s long-term lodgers or short-term guests via platforms like Airbnb, unauthorised subletting can create serious issues.

From unexpected wear and tear to potential legal consequences, subletting without consent can turn your investment into a liability. At Private Investigators UK, we’re often called upon to discreetly confirm whether subletting is taking place — and if so, to provide the proof landlords need to act confidently.

What Exactly Is Subletting?

Subletting is when your tenant rents out all or part of your property to someone else. The original tenant effectively becomes a “landlord” to the subtenant. In some cases, this might involve a formal agreement between them — in others, the arrangement is informal and unregulated.

Subtenants usually have exclusive rights to the room(s) they occupy, and they pay rent to the original tenant — not you. With today’s rental prices, this can be a tempting way for tenants to make extra income. Some sublet long-term, while others take advantage of short-term letting apps.

Is Subletting Without Permission Illegal in the UK?

Subletting in itself is not illegal — but doing it without your permission often breaches the tenancy agreement. Most contracts clearly state whether subletting is allowed, and under what conditions.

If a tenant breaks this agreement, you may have grounds to begin eviction proceedings. But before taking action, it's crucial to gather reliable evidence.

Why Unauthorised Subletting Is a Problem

Subletting without your knowledge can lead to a number of issues, including:

• Subtenants with no verified background or credit checks
• Uncertainty around who is living in the property
• Increased wear and tear, property damage, or illegal activity
• Potential violation of HMO (House in Multiple Occupation) rules
• Voided landlord insurance due to unapproved occupancy

One of the most serious risks is unknowingly running an illegal HMO. Under UK law, a property becomes an HMO when it is occupied by at least three unrelated individuals who share facilities. If unlicensed, the fines can be severe — sometimes exceeding £20,000.

Common Signs Your Tenant May Be Subletting

While it's not always easy to prove subletting, certain red flags should raise your suspicion:

• Multiple people seen entering and exiting the property regularly
• Mail or parcels addressed to unknown names
• Locks on internal bedroom doors
• Tenants evasive about who else is living there
• The property appears frequently on short-let sites

If you’ve noticed any of these signs, it may be time to look into it more thoroughly.

How Can a Private Investigator Help?

Many landlords come to us when they suspect subletting but don’t have clear proof. Confronting a tenant without evidence often results in denial — or worse, retaliation.

Our private investigators can carry out discreet residency checks and surveillance to confirm exactly who is living at your property, and when. If subletting is happening, we’ll gather evidence such as photographs, movement logs, and witness reports — all admissible in court if needed.

Can I Evict a Subtenant?

You can’t evict a subtenant directly unless you have a legal relationship with them — but you can evict your original tenant for breach of contract. Once they leave, the subtenant has no legal right to remain unless they’re on a new agreement with you.

If damage has occurred, or if the situation has put your insurance at risk, taking legal action may be necessary. Having documented evidence from a licensed investigator can strengthen your case significantly.

Need Help? Get in Touch

If you’re worried that your tenant might be subletting your property behind your back, don’t let the situation escalate. Contact us for a free, no-pressure quote. We’ll assess your concerns, offer clear guidance, and if needed, deploy one of our specialist team members to discreetly investigate.

Whether it’s short-term lets, unauthorised lodgers, or potential HMO violations — we’re here to help landlords stay informed and protected.