Harrow HMO Licence: Mandatory, Additional and What Happened in August 2026

Harrow runs two HMO licensing regimes under Part 2 of the Housing Act 2004 — mandatory licensing and additional licensing — and they operate on completely different timelines. Mandatory licensing is permanent. Additional licensing expired on 5 August 2026, and as of October 2026, no replacement designation is in force.

That gap catches landlords who assume both schemes are live.

Mandatory HMO Licensing

Mandatory HMO licensing applies borough-wide across all 22 Harrow wards and has no expiry date. If a property houses five or more people forming two or more separate households who share basic amenities (kitchen, bathroom, toilet), it needs a mandatory HMO licence.

A "household" under Section 258 of the Housing Act 2004 means family members — partners, relatives, stepchildren. Unrelated sharers each count as their own household. So five unrelated individuals sharing a house form five households, triggering the mandatory threshold.

The total fee for a mandatory HMO licence in Harrow is approximately £1,900, and the licence runs for up to five years. An inspection by an Environmental Health Officer is part of the process, costing £500 for a standard HMO or £100 per self-contained unit.

Additional HMO Licensing — Currently Lapsed

Harrow's borough-wide additional HMO scheme came into force on 6 August 2021 and expired on 5 August 2026. The council ran a public consultation on renewing it between December 2025 and February 2026, and a Cabinet vote was scheduled for May 2026, but no active replacement designation was in place as of October 2026.

Additional licensing targeted smaller HMOs — specifically properties occupied by three or four people forming two or more households sharing amenities. While the additional scheme was live, these smaller shared houses needed a licence borough-wide. With the scheme currently lapsed, these properties fall through to selective licensing rules: if the property is in one of the six designated selective wards, it needs a selective licence; if it's in a non-designated ward, no local licence is required.

Landlords should watch for a new additional HMO designation order. If Harrow re-designates, the obligation will return borough-wide.

How the Schemes Overlap

The classification follows a strict hierarchy:

1. Five or more people, two or more households, shared amenities → mandatory HMO licence (borough-wide, always active)
2. Three or four people, two or more households, shared amenities → additional HMO licence if the scheme is active (currently lapsed); otherwise selective licence if in a designated ward
3. Single household or two sharers, non-HMO → selective licence if in a designated ward; no local licence if outside

An HMO licence under Part 2 displaces any selective licence requirement under Part 3 — you never need both for the same property.

What About Section 257 Buildings

Converted buildings — blocks of flats where the original conversion didn't meet the Building Regulations 1991 (or later regulations where applicable) and less than two-thirds of the flats are owner-occupied — fall under Section 257 HMO rules. These are included in Harrow's Part 2 licensing framework when more than one-third of the flats are let on short tenancies. Specific fee scales apply.

If you're a leaseholder in a converted block, the licensing obligation typically sits with the freeholder, not individual flat owners. But the situation depends on the management structure, so it's worth checking directly with Harrow's Private Sector Housing team.

Our Harrow landlord licensing guide walks through the full classification hierarchy, including the decision framework for working out which licence your property needs and what to do during the additional scheme gap.

See more England guides →