Does the landlord pay council tax on an HMO?

In England, regulations in force from 1 December 2023 treat HMOs covered by them as a single dwelling for council tax and put the liability on the landlord. In Wales, the owner liability rules for HMOs sit in the Council Tax (Liability for Owners) Regulations 1992. Scotland has its own rules. In every case, confirm the band and who is liable with the council before you set room rents.

Is gross yield a good way to compare HMOs?

Only as a first filter. Gross yield ignores bills, voids, management and finance, which are much heavier in a bills-inclusive HMO than in a single let. In the illustrative example above, a gross yield of about 13.1% becomes a net yield of about 5.8% and cash flow of about £345 a month before tax.

How much should I allow for empty rooms?

There is no single right figure. Use your own letting history or local evidence for similar rooms, then test a worse case. The example uses 3 empty room-months out of 60 as an assumption, not a benchmark. Remember that most bills keep running when a room is empty.

How to calculate HMO cash flow after bills and costs

Q: Is HMO cash flow the same as profit for tax?

No. Cash flow here is before personal tax. Taxable profit is worked out under different rules: for example, individual landlords cannot deduct mortgage finance costs from rental income and instead get a basic rate tax reduction. Speak to a qualified tax adviser about your own position.

HMO cash flow after bills is the rent you actually collect from each room, minus every bill and running cost you pay as landlord, minus your mortgage payments. In a bills-inclusive HMO that means utilities, council tax, broadband, cleaning, management, maintenance, licensing and compliance all come out of the rent before anything is left over. The answer is cash flow before personal tax, so it is not what you keep. Start from room-by-room rent received, not the headline rent, because an empty room cuts income while most bills keep running.

Check which HMO rules apply first

Licensing and council tax both change your costs, so confirm the rules for where the property is before you build a forecast. This article uses England as the main example.

England. GOV.UK describes an HMO as a property rented out by at least 3 people who are not from 1 household and who share facilities such as the bathroom and kitchen. A mandatory HMO licence is needed where 5 or more people forming more than 1 household live there, some or all share toilet, bathroom or kitchen facilities, and at least 1 tenant pays rent. Councils can also require licences for smaller HMOs in their area, so check with the council. A licence lasts a maximum of 5 years, and renting out an unlicensed HMO that needs a licence can lead to an unlimited fine.
Wales. Wales has its own prescribed description for mandatory licensing: the HMO (or part of it) has 3 or more storeys and is occupied by 5 or more people living in 2 or more households. Welsh councils can run additional licensing for other HMOs.
Scotland. Scotland has a separate HMO licensing regime. GOV.UK describes a licensable HMO there as a property rented out by at least 3 unrelated people who share the bathroom or toilet and kitchen. A licence usually lasts 3 years and you apply to the council.
Northern Ireland has its own HMO regime, which this article does not cover.

Local planning rules can matter too. If you invest in Liverpool, read our guide to Liverpool HMO rules and Article 4. For the wider picture, see our guide for HMO investors.

Step 1: Work out rent received, room by room

Do not multiply one room rent by the number of rooms and call it income. Build it up room by room:

List every room and its rent. Ensuite and larger rooms usually let for more than small rooms. Use rents you have achieved or can evidence locally, not hoped-for figures.
Estimate months let for each room. Rooms turn over more often than whole houses, and each change of tenant can leave a gap. Allow for this per room.
Allow for arrears. If a tenant does not pay, you have charged the rent but not received it.
Add the rooms together. This is annual rent received. Compare it with full occupancy so you can see the cost of voids in pounds.

Step 2: List the bills you pay in a bills-inclusive HMO

When rent includes bills, these are your costs, not the tenants'.

Utilities

Gas, electricity and water. Usage depends on how many tenants you have, the season and how efficient the house is. Use past bills where you have them. If prices rise during a tenancy, you carry the increase until you can review rents.

Council tax

In England, regulations that came into force on 1 December 2023 treat HMOs covered by them as a single dwelling for council tax and place liability on the landlord. Self-contained flats that fall under section 257 of the Housing Act 2004 are outside these regulations. In Wales, the owner liability rules for HMOs are in the Council Tax (Liability for Owners) Regulations 1992. Scotland has its own council tax rules. Ask the council which band applies and who is liable before you set your rents.

Broadband and other services

Broadband is often part of a bills-inclusive offer. Include any other services you provide, such as a TV package.

Cleaning and gardening

Regular cleaning of shared kitchens, bathrooms and hallways, and any garden upkeep, are ongoing costs in many HMOs.

Step 3: Add the running costs

Management. If an agent manages the HMO, the fee is often a percentage of rent collected. Check whether it is charged on rent received or rent due, and what extra fees apply for new tenancies.
Maintenance and repairs. More people means more wear on kitchens, bathrooms and flooring.
Replacement fund. Set aside money for furniture, white goods, carpets and decoration, which wear out faster in shared homes.
Insurance. Check that the policy covers letting to multiple sharers as an HMO.
Licensing. Spread the licence fee across the years it covers. If the licence lasts 5 years, divide the fee by 5 for an annual cost.
Compliance. Licence conditions include sending the council an updated gas safety certificate every year and installing and maintaining smoke alarms. In England, electrical installations must be checked at least every 5 years by a qualified person. Include fire safety equipment servicing and any works the council requires as a licence condition.
Ground rent and service charge if the HMO is leasehold.

Step 4: Add finance costs

Use your actual monthly mortgage payment.

On an interest-only mortgage, the payment is interest only.
On a repayment mortgage, the payment includes capital. That lowers cash flow even though it reduces your debt.
If your fixed rate ends within your forecast period, test a higher rate. Our guide to calculating rental cash flow covers this in more detail.

Step 5: Keep your definitions consistent

Mixing measures is the most common reason HMO forecasts look better than reality.

Measure	What it means here
Gross rent	Rent charged before any costs, at full occupancy
Rent received	Rent actually collected after voids and arrears
Gross yield	Annual gross rent ÷ purchase price × 100
Net yield	(Rent received minus operating costs, excluding mortgage) ÷ purchase price × 100
Cash flow	Rent received minus operating costs (including all bills) minus mortgage payments, before personal tax
Capital growth	Change in the property's value, separate from cash flow

Tax is separate again. For example, individual landlords cannot deduct mortgage finance costs from rental income; instead they get a basic rate tax reduction. So taxable profit is not the same as cash flow. Our landlord tax return checklist explains what to keep for your records.

One-off costs such as the deposit, stamp duty, furnishing and the first licence application are not monthly cash flow. They belong in the total cash you put in.

Illustrative example: a five-bedroom, bills-inclusive HMO in England

Illustrative example. These figures are invented to show the method. They are not typical rents, costs or returns for any area.

Assumptions

Purchase price: £250,000
Deposit: 25% (£62,500); loan £187,500
Mortgage: interest-only at 5.5% a year (£10,312.50 a year)
Five rooms let to five separate tenants (so a mandatory licence applies in England)
Room rents, all bills included: £600, £600, £525, £525 and £475 a month (£2,725 a month in total)
Voids: Room 3 empty for 1 month and Room 5 empty for 2 months in the year; no arrears
Management: 12% of rent received
Bills and running costs as listed in the cost table below

Rent received, room by room

Room	Rent per month	Months let	Rent received
1 (ensuite)	£600	12	£7,200
2 (ensuite)	£600	12	£7,200
3	£525	11	£5,775
4	£525	12	£6,300
5	£475	10	£4,750
Total	£2,725	57 of 60	£31,225

Full occupancy would be £32,700 a year, so the voids cost £1,475.

Annual costs

Cost	Annual amount
Gas and electricity	£3,600
Water	£720
Council tax	£2,100
Broadband	£480
Communal cleaning (fortnightly)	£1,560
Management (12% of £31,225)	£3,747
Maintenance and repairs	£2,400
Replacement fund	£600
Insurance	£900
Licence fee (£1,000 spread over 5 years)	£200
Compliance (gas safety, electrical check spread over 5 years, fire alarm servicing)	£460
Total operating costs	£16,767
Mortgage interest	£10,312

Result

Measure	Figure
Gross yield (£32,700 ÷ £250,000)	13.1%
Rent received minus operating costs	£14,458
Net yield (£14,458 ÷ £250,000)	5.8%
Cash flow before tax	£4,146 a year (about £345 a month)

What if things change?

Interest rate rises to 7%: interest becomes £13,125, and cash flow falls to about £1,333 a year (about £111 a month).
Six more empty room-months (at the average room rent of £545): rent received falls by £3,270, management falls by about £392, and cash flow drops to about £1,268 a year (about £106 a month). The bills barely change, which is why voids hit HMO cash flow so hard.

A headline gross yield above 13% becomes a few hundred pounds a month before tax, and small changes can remove most of it.

Quick checklist

Rent built up room by room, using evidenced rents
Voids and arrears allowed per room
Gas, electricity, water, council tax and broadband included at realistic levels
Cleaning, management, maintenance and a replacement fund included
Licence fee spread over its term, plus yearly compliance costs
Mortgage at today's rate and at a higher test rate
Cash flow labelled as before tax; capital growth and tax kept separate
Licensing, planning and council tax position confirmed with the council

How PROXERA can help

The PROXERA deal analyser has an HMO mode for this calculation. Enter the number of rooms, the average rent per room (£545 in the example), occupancy, a void allowance, utilities, management, insurance, maintenance and licensing fees. It returns gross and net yield, monthly cash flow and cost payback. There is no separate council tax or broadband field, so include council tax, broadband, cleaning and compliance in "Utilities (all bills)" or "Other Monthly Costs". Once the HMO is let, you can record the actual rent and costs in a free PROXERA account and compare them with your forecast.

Run your HMO numbers in the deal analyser (HMO mode)

Information, not advice. This article is general information. It is not a personal recommendation and does not constitute financial, investment, mortgage, tax or legal advice.