Smoke and carbon monoxide alarms for landlords: records and tax

acrenvo.com/guides/smoke-and-co-alarm-records, last reviewed 20 October 2026

Malik is fictional, but his routine is a sensible one. He lets a two-storey house with a wood-burning stove in the sitting room. On the first day of each new tenancy he walks round with the tenant, presses the test button on every alarm and notes it on the inventory. Unlike a gas or electrical check, this duty has no fixed cycle of its own, so he wants to be sure he is keeping the right record. He also wants to know how the cost of a new alarm should go into his records for Making Tax Digital (MTD) for Income Tax. This guide covers those points for landlords in England.

Which alarms a landlord must provide

GOV.UK’s summary of a landlord’s duties says it is your responsibility to “fit and test smoke alarms and carbon monoxide alarms”. The rules come from the Smoke and Carbon Monoxide Alarm (England) Regulations 2015, as amended in 2022, and GOV.UK’s question-and-answer booklet, last updated on 29 July 2022 and read again on 20 October 2026, sets out three duties for every relevant landlord:

• Ensure at least one smoke alarm is equipped on each storey of their homes where there is a room used as living accommodation.
• Ensure a carbon monoxide alarm is equipped in any room used as living accommodation which contains a fixed combustion appliance (excluding gas cookers).
• Ensure smoke alarms and carbon monoxide alarms are repaired or replaced once informed and found that they are faulty.

The booklet leaves the choice of alarm to the landlord: “The regulations do not stipulate the type of alarms (such as mains powered (‘hard-wired’) or battery powered) that should be installed.” It does give one preference, though: “Where battery powered alarms are selected, alarms with ‘sealed for life’ batteries rather than alarms with replaceable batteries are the better option.”

When the alarms must be checked

This is the duty that sets Malik’s routine. The booklet says: “The regulations require checks to be made by or on behalf of the landlord to ensure that each prescribed alarm is in proper working order on the day the tenancy begins if it is a new tenancy.” During the tenancy the duty changes from testing to putting things right: “Landlords will be responsible for repairing or replacing any faulty alarms.”

That is why the compliance tracker treats alarms as a checklist for each new tenancy rather than a date that repeats. Provide the required smoke and carbon monoxide alarms, check them on the first day of a new tenancy, and repair or replace a reported faulty alarm.

The record to keep

The booklet is clear that the evidence is the landlord’s job: “It is the responsibility of landlords to keep a record of when alarms are tested.” It suggests one way of doing it, which is the method Malik uses: “One possible means, if the landlord goes through the inventory on the first day of the tenancy, is that the landlord makes provision for the tenant to sign the inventory to record that the required alarms have been tested by the landlord and the tenant is satisfied they are in working order.”

A signed inventory, a dated note of each test and the receipt for any alarm you replace together give a clear account if the council ever asks.

What alarms cost

No government source gives a price for smoke or carbon monoxide alarms, or for having them fitted, so the cost varies and we do not state one. The price is set by whoever sells or fits them, and we do not recommend or list products or installers.

How the costs are treated for tax

GOV.UK’s guidance on working out rental income does not mention alarms by name, so the answer comes from its general rule: “You can deduct expenses from your rental income when you work out your taxable rental profit as long as they are wholly and exclusively for the purposes of renting out the property.”

The harder question is whether an alarm is a repair or a capital cost, and GOV.UK does not answer it for alarms in particular. It says: “Allowable expenses include the costs of maintenance and repairs to the property (but not ‘capital’ improvements).” and “A repair restores an asset to its original condition, sometimes by replacing parts of it.” On the other side of the line, it says: “Expenses are ‘capital expenses’ if they will be used in the business over a longer period of time, such as when you:”

• add something to the property that was not there before
• alter, improve or upgrade something that was existing
• include the purchase of furnishings and equipment for the property

It goes on: “Capital expenses are not allowable and cannot be claimed against your rental income but you should keep records of them as you might be able to set them against Capital Gains Tax if you sell the property in the future.” If you are unsure which side a particular purchase falls on, HMRC or a tax adviser can tell you. Fines follow a rule of their own, and HMRC’s manual says: “A customer can’t deduct the cost of a fine incurred as a result of their breach of the law.”

One email a month lists the MTD software price changes we have checked and any changes to HMRC’s list of software. If that would be useful, you can sign up for the monthly price-changes email at the end of this page.

Recording the costs under Making Tax Digital

Each receipt becomes a digital record in your software, like any other property cost. GOV.UK says: “When you create records of your income or expenses, you will need to record the:”

• amount
• date when the income was received or expenses incurred
• category (the type of category you use depends on the type of business you have)

It adds: “Making Tax Digital for Income Tax uses the same categories of income and expenses as Self Assessment.” The receipts and the signed inventory are worth keeping together. For tax purposes, GOV.UK says: “You will need to keep your digital records for at least 5 years after the 31 January submission deadline for a tax year. This is the same amount of time you need to keep records for Self Assessment.” The guide to MTD digital records explains the rest of what a record needs.

If your property is outside England

This guide covers England only, and the regulations it describes are the Smoke and Carbon Monoxide Alarm (England) Regulations 2015, as amended in 2022. GOV.UK’s guide to renting out a property says there are different rules for landlords in Scotland and for landlords in Northern Ireland.

The other recurring checks

• Gas safety checks for landlords: costs, records and tax
• Electrical safety reports (EICR) for landlords: costs, records and tax
• Energy Performance Certificates for landlords: costs, records and tax
• Property licences for landlords: costs, records and tax
• Tenancy deposit protection for landlords: costs, records and tax

The compliance tracker keeps the dates for all of these checks together, property by property.

Questions about smoke and carbon monoxide alarms