UK SIC 2007 · 81221
Window cleaning services (SIC code 81221)
Window cleaning services is UK SIC code 81221. It sits in division 81 (Services to buildings and landscape activities) of the SIC 2007 list. On the August 2026 Companies House register, 4,882 active UK companies list 81221 among their SIC codes. 2,760 of them list it first.
This division is home to the cleaning and grounds trades. General building cleaning sits under 81210. Code 81299 collects other cleaning services. Code 81222 marks specialised work such as trauma, industrial or high-level cleaning. Window cleaners use 81221. Wider building and industrial cleaning uses 81229. Landscapers, one of the biggest groups here, register under 81300. Code 81100 marks combined facilities support providers. They bundle cleaning, maintenance and reception into one contract, and they are usually the largest companies in the division.
Who prospects SIC 81221 companies
These are classic local service businesses, so the sellers are familiar ones. Insurance brokers offer public liability. Accountants chase new incorporations. Job scheduling and quoting apps, equipment and chemical suppliers, and franchisors recruiting operators all work the same lists. Commercial cleaning and facilities firms also appear on procurement radars, when offices, schools and managing agents look for contractors. A weak website usually marks a word-of-mouth operator, and the poor-website filter finds the audience that website builders and local SEO services convert best. Growth marks firms moving from domestic work into contracts.
Lead generation for trades & construction →How to read SIC 81221
SIC 81221 is a five-digit code, and the digits are not arbitrary. The first two, 81, are the division, services to buildings and landscape activities. Add the third and you have group 812; the fourth narrows it to a class, and the fifth to the subclass, which is the level Companies House actually asks a company to pick. The whole division sits under section N, administrative and support service activities, the broadest tier there is. Reading a code left to right therefore goes from a whole sector down to one activity.
A company chooses its own codes when it incorporates and can change them on any confirmation statement. It may list up to four, and Companies House does not check whether they are right. That is why 81221 is worth reading as a claim the company made about itself rather than as a verified fact, and why the first-position and any-position counts above differ.
Measured on the August 2026 register, the busiest registered-office post towns for 81221 are London (652), Birmingham (78), Glasgow (63), Manchester (62) and Bristol (57). Those are registered-office locations, which is where the paperwork sits rather than necessarily where the work happens, so treat them as where to start looking rather than as a service area.
Using SIC 81221 as a filter
4,882 companies is 0.09 per cent of the 5,190,464 active companies on the UK register, and ranks 81221 7th most used of the 8 codes we track in division 81. That is the pool before any filter. Whether it is a big market for you depends on what you sell, but it is the number every other filter on this page cuts down from.
Only 2,760 of the 4,882 companies carrying 81221 put it first. The other 2,122, 43 per cent, list it behind another code, which usually means the business does more than one thing and files 81221 as a sideline. A search that matches the first code only will miss most of this population, so match on any of the four SIC positions and use a second filter to tighten it.
These companies are spread out. London is the largest single cluster at 13 per cent and the top five post towns together hold only 19 per cent, so the remaining 81 per cent sits across the rest of the country. A regional filter narrows this list without gutting it, which makes it a reasonable code to work territory by territory.
In practice the code on its own is rarely the whole filter. Pair 81221 with an incorporation date to catch companies in their first months, when they are still choosing suppliers, or with a filing deadline to reach them while the year end is on their mind. A worked example for this code: 81221, registered office in London, incorporated in the last ninety days, which turns a 4,882 company pool into a list you can write to in an afternoon. Add the poor-website filter if what you sell is a website, or a recent change of officer if you sell to whoever just took the job. Every company you pull carries the Companies House record, the director's name, a verified website and a verified email, and the ones we cannot complete are not charged.
Where SIC 81221 clusters in the UK
ACTIVE COMPANIES BY REGISTERED-OFFICE POST TOWN · COMPANIES HOUSE REGISTER, AUGUST 2026
SIC 81221 companies, as leads
Live rows from the enriched register. Email and phone values are withheld until you sign up.
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About SIC 81221
How many UK companies use SIC code 81221?
4,882 active UK companies list 81221 (Window cleaning services) among their registered SIC codes. Each company may register up to four. Of those, 2,760 put it first. The figures come from the August 2026 Companies House register snapshot, and count active companies only.
Which SIC code should a domestic cleaning company use?
Most domestic and general cleaners register 81210, general cleaning of buildings. Code 81299 covers services that fit no standard category. Code 81221 is specifically for window cleaning. There is no penalty for a wrong answer. Companies House runs no approval process, and you can refine your codes on any confirmation statement (CS01). Firms covering several trades often list two or three codes, up to the maximum of 4.
Is landscaping under this division or under construction?
Ongoing landscape services sit under 81300 in this division. That means planting, grounds maintenance and gardening for clients. Hard landscaping is really construction work. Building patios, driveways or retaining walls fits division 43 codes better. Landscape design belongs with the architects under 71112. A firm that designs, builds and maintains can hold codes from more than one division.
Find UK SIC 81221 companies
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