for REALM 47 Group updates, including investment opportunities:

Subscribe For Updates

Everything You Need to Know About a “HMO” Certificate of Lawfulness

Sara NewsonBy Sara Newson on 16 May 2024

Everything You Need to Know About a “HMO” Certificate of Lawfulness

If you’re planning to purchase an HMO in the UK, you might have come across the terms “Certificate of Lawfulness” or “Certificate of Lawful Use.”

But what is it? Do you need it? Does it expire? How do you get it? It can feel like a bit of a minefield, so we have put together this guide telling you everything you need to know.

A bit of history…

Here’s a bit of a history lesson to start off with! In 2010, when the Labour government were exiting and the Conservatives were coming in, Labour decided to push through a final act: planning permission for 3-6 person HMO’s. These HMO’s no longer sat in the residential dwelling planning use class of C3 but in the new use class – C4. This meant that any new HMO’s created required planning permission (this was not retrospective so any already in operation automatically had permission). When conservatives came into power they immediately set about helping their landlord supporters with a compromise: permitted development. Which overrides the need for planning permission.

However, alongside this comes Article 4 (A4), which gives local councils the ability to remove permitted development rights in areas of high concern, this is a standardised practice and is not limited to HMO’s but all permitted development rights. There were areas of high concentration of student houses that were causing local residents issues with anti-social behaviour, noise and poor waste management – this was termed over-studentification. In order to implement A4, the council must go through a 12 month consultation period putting forward a strong case for bringing it in.

So, if you’re looking to buy or create an HMO, it’s important to check whether A4 is in place in that postcode before you proceed. Each local authority will have its own way to check through their website. And, if you’re buying an existing HMO in an A4 area, it’s imperative to check that the property has a Certificate of Lawfulness in place, or that you can be provided with the sufficient evidence to obtain one, should you need to in the future.

What is a Certificate of Lawfulness?

A Certificate of Lawfulness (COL) is a document provided by the local council or local authority confirming that:

The proposed or current use of a building is lawful
It does not need planning permission
The property has been legally changed within its use class
It has been consistently used in that use class

Is it mandatory?

While a Certificate of Lawfulness is not a legal requirement, it can be very beneficial. It can help you to avoid neighbourly disputes, as neighbours cannot object to COL applications like they can Planning Permission applications. It can also provide reassurance to potential buyers if you are selling the property post-development, as it brings peace of mind that your property is legally compliant. It can also aid with remortgaging and selling a HMO as it evidences to mortgage lenders that the HMO is a legal one.

Does it expire?

A Certificate of Lawfulness does not expire, but if you are found to have withheld information during your application, or you have provided misleading information, then your local authority has the right to revoke your certificate.

It’s also worth noting that property regulations do change, so while the certificate ensures your development adhered to regulations at the time of issue, it’s important to stay aware of changes to property regulations to ensure your property continues to fall within the current rules.

How do I get a COL?

To obtain a Certificate of Lawfulness you must submit sufficient evidence to the relevant local authority. The review process can take around 8 weeks, so it’s important to submit your application at least 2 months before you need it.

To apply, you can download an application form from your local authority, and submit this along with your evidence and the required fee.

One of the main reasons for rejecting a COL application is lack of sufficient evidence. We would recommend submitting as much evidence as possible, including: a cover letter detailing the dates the property was converted, an overview of the management, the ownership and the consistent use, tenancy agreements, deposit protection certificates and deposit release date evidence, check out statements, and statutory declarations. With some article 4 areas now being over 10 years old, you only need to provide up to 10 years evidence as this is a standard planning law which will override the article 4 implementation date.

If you’re still a bit unsure, don’t worry! Here at Realm 47, as your investment agent, we do all of these checks as part of our due diligence, helping sellers to compile the information if needs be. Properties go through rigorous checks before being offered to our client base, please email us at if you’d like us to help you to secure your next HMO.