An improvement notice is served under sections 11 or 12 of the Housing Act 2004 after the council has inspected and found a hazard under the Housing Health and Safety Rating System (HHSRS).
It is not a warning letter. It is a legal instrument with a compliance date, an appeal window and a criminal offence attached to ignoring it.
Category 1 and category 2
HHSRS scores hazards into bands. Category 1 is the serious tier and the authority has a duty to act. Category 2 is less serious and the authority has a power to act.
Practically: a category 1 notice is not going away, and arguing that the hazard is minor is arguing about the score rather than the notice.
What the notice must contain
- The hazard, and whether category 1 or 2.
- The remedial action required.
- The date the notice takes effect — at least 28 days after service.
- The date by which work must start, and be completed.
- The right of appeal and the period for it.
If any of that is missing or wrong, that is appeal material.
The 21 days
You have 21 days from service to appeal to the First-tier Tribunal. Grounds include that the hazard does not exist or is wrongly categorised, that the required action is unreasonable, that you are not the appropriate person, or that someone else should bear the cost.
Miss it and the notice stands whatever its merits. This is the single most consequential date in the process and it runs from service, not from when you opened the envelope.
What ignoring it costs
Failure to comply is an offence under section 30. It attracts a civil penalty of up to £30,000 under s.249A, or prosecution.
Worse, the council can do the work itself under section 31 and recover the cost from you — with the cost recoverable as a charge on the property. You lose control of scope and price, and the debt attaches to the asset.
A notice on the register also affects sale and refinancing, which is often the consequence that lands hardest.
Doing the work is not the same as complying
Compliance means the specified action, done by the specified date, and the council satisfied. Landlords who do something, do it late, or do a different thing they consider better, remain in breach.
If the specified action is wrong, the answer is to appeal or negotiate a variation — not to substitute your own remedy and hope.
What to do, in order
- Diarise the 21 days today. Everything else can wait a day; that cannot.
- Read what is actually required, and by when.
- Contact the officer. Most will discuss timescales for a landlord who engages. Non-engagement is what escalates cases.
- Get quotes immediately — availability is a real constraint and is not a defence.
- Appeal if the notice is wrong, on grounds, within 21 days.
- Confirm completion in writing and ask for confirmation the notice is satisfied.
- Keep everything dated. The same records answer an ombudsman complaint and an Awaab's Law timescale.
Wales
HHSRS and the Part 1 enforcement regime apply in Wales, so improvement notices work the same way. Welsh landlords also face Rent Smart Wales consequences, since enforcement action can affect a licence.
Price what else is exposed. The fine calculator shows your position with the instrument beside every figure.
Information tool, not legal advice. If a notice has been served, take advice on your specific facts.