HMO mortgages

What counts as an HMO

A HMO (House in Multiple Occupation) is, in the simplest definition, a property occupied by three or more tenants forming more than one household, sharing a kitchen or bathroom. A "large HMO" (5 or more tenants) requires a mandatory licence from the local authority. Many councils also require licences for smaller HMOs under additional or selective licensing schemes. Lender appetite varies sharply by HMO size, council area and licensing status.

Local-authority licensing tiers

Three tiers of licence to be aware of. Mandatory HMO licensing applies nationally to large HMOs (5 plus tenants from 2 plus households). Additional HMO licensing is set by individual councils to cover smaller HMOs (often 3 to 4 tenants); councils declare these schemes for defined geographic areas, typically 5-year terms. Selective licensing is the broadest: it can apply to all rented properties in a defined zone, regardless of HMO status. Council-by-council variation is significant. Two streets apart in the same town can carry very different licensing obligations. Always check the council planning and licensing pages before you offer.

Lender appetite

Mainstream lenders fund small (3 to 4 bed) HMOs at standard buy-to-let pricing. Specialist HMO lenders fund larger licensed HMOs (5 to 8 beds) and use a "commercial" or "investment" valuation, which values the property on its rental income rather than comparable sales. This often makes HMOs viable that would never stack on a bricks-and-mortar valuation.

Yields and stress tests

HMOs often generate higher gross yields than single-let properties, although actual yields vary significantly by location, property type and management model. The ICR (Interest Cover Ratio) stress test still applies, but the larger rent figure usually means HMO cases pass ICR comfortably. The trap is using all-rooms-let rent in the calculation; lenders typically apply a vacancy allowance to the rental figure used in affordability calculations, and the level applied varies by lender.

Worked example, a 5-bed licensed HMO

Property £320,000, 5 rooms at £625 a month each fully let (£3,125 a month, £37,500 a year). Lender applies a 12% void haircut: £33,000. Mortgage at 75% LTV: £240,000. Stress rate 5.5%, annual stressed interest £13,200. ICR at 145% requires rent of £19,140; the case clears comfortably at £33,000. Compare with the same property as a single let at £1,650 a month: £19,800 a year, ICR cover 150%. The HMO clears more easily and produces £13,200 more annual gross rent. The trade-off is the licensing cost (typically £500 to £1,500 for a 5-year licence), the fire-safety upgrade cost (often £5,000 to £15,000 for fire doors, alarm system and emergency lighting), and the materially higher management workload.

Stress-rate variation across lender types

Mainstream buy-to-let lenders typically stress at 5.5% with 145% cover for higher-rate taxpayers. Specialist HMO lenders often use lower stress rates (4.5% to 5.0%) on the basis that HMO yields are more predictable, with cover ratios at 125% to 130%. The lender choice can move maximum borrowing by £30,000 to £60,000 on the same rent figure. We pick the lender whose stress test fits.

Licensing, AST structure and fire safety

Each tenant is usually on a separate AST (Assured Shorthold Tenancy) with a defined room and shared use of common areas. Mandatory HMO licences require fire doors, fire alarms, minimum room sizes and adequate kitchen and bathroom provision. Lenders increasingly want to see the licence before completion, or evidence of a pending application. Article 4 directions in some council areas remove permitted-development rights to convert a house to an HMO; planning permission is then required, which can delay or block the conversion entirely.

Common pitfalls we see

Buying in an Article 4 area without realising planning permission is required for the HMO conversion. Underestimating the upfront fire-safety upgrade cost. Picking a mainstream buy-to-let lender whose policy excludes 5-plus bed HMOs. Using full-occupancy rent for ICR rather than the lender voids-adjusted figure. Not lining up a HMO-experienced letting agent before completion. We work all five before the application.

Buy-to-let warning

Most buy-to-let mortgages, including HMO mortgages, are not regulated by the Financial Conduct Authority. The yield is attractive but the operational and regulatory burden is materially higher than a single let. Take legal advice on local licensing rules before you offer.