Five checks before you pay a deposit to a London trade

Every bad building job in London has the same shape. A price that felt keen, a deposit paid in good faith, and then a slow realisation that the person holding your money is harder to reach than they were when they wanted it.

Reviews will not protect you here. They are easy to buy, easy to farm from friends, and they tell you about jobs that are not yours. What protects you is ten minutes of checking before the money moves.

1. Check the company actually exists, and for how long

Companies House is the statutory register of UK companies. In its own words it exists to "incorporate and dissolve limited companies" and to "register company information and make it available to the public". Search the register for the name on the quote.

What you are looking for is less about a clean record than about consistency. Does the company exist at all? How long has it been incorporated? Is it active, or dissolved, or in the course of being struck off? Are accounts and confirmation statements filed, or overdue? Has it traded under previous names?

A company incorporated three weeks ago is not automatically a bad bet, but it does mean there is no track record behind the quote, and that should change what you are willing to pay up front.

2. Do not trust the registered address as a location

The address on the register is the registered office: the place that receives statutory mail. For a great many small firms that is their accountant's office or a company formation agent, sometimes in a different part of the country. It is not evidence of a local presence, and it is not where anyone works.

If you want to know where a business actually operates, look for a trading address on its own website, and treat the two as answers to different questions.

3. Check trade registrations on the register's own site

Some work is not legal for an unregistered person to do. Gas work is the clearest case: the Health and Safety Executive points consumers to the Gas Safe Register as the register for domestic gas engineers. Electrical work in homes is covered by competent person schemes whose members self-certify against the building regulations.

The important part is the method, not the name of the scheme. Ask for the registration number, then check that number on the scheme's own website. Do not accept a photograph of a card, a logo on a van or a badge in a website footer. Any of those can be copied in a minute; a register entry cannot.

4. Ask for the insurance certificate, not the reassurance

"We're fully insured" is a sentence, not a policy. Ask for the public liability certificate and read three things on it: the insurer's name, the cover limit, and the dates. Cover that lapsed last spring is worth nothing, and a limit well below the value of your property is worth less than it sounds.

If the job involves structural work, ask who carries the professional indemnity for the design decisions, which is a different policy and often a different company.

5. Make the quote specific enough to argue with

A quote that reads "supply and fit new bathroom, £9,500" is not a document you can enforce. One that lists what is included, what is excluded, who supplies the materials, the make and model of the key items, how long the work should take and what happens if it overruns, is.

Get it in writing before any money moves, and keep the written version. Where there is a deposit, agree what it is for. A deposit that covers ordered materials is reasonable and should be evidenced. A large deposit that is simply the first slice of the price is a transfer of risk to you.

How you pay matters

Staged payments against completed milestones keep both sides honest. Paying a large sum in cash removes the paper trail and most of your recourse at once. Card and bank payments leave a record, and card payments may give you an additional route to dispute.

The London-specific bits people forget

Three things catch London jobs in particular. Parking: many trades need a bay suspension or a dispensation from the borough, which takes days to arrange and costs money that should be in the quote. Waste: a skip on the public highway needs a permit from the borough, and fly-tipped waste traced back to your address becomes your problem, so ask who is carrying the waste away and under what licence. Access: in flats and conversions, work often needs the freeholder's consent, and a trade that has not asked about this has not finished thinking about your job.

In conservation areas and on listed buildings, replacing windows or altering a frontage may need consent in its own right. A trade that shrugs at that question is telling you something.

What none of this proves

These checks establish that a real, insured, registered business is quoting you a specific price for specific work. They do not establish that the work will be good. For that, the most useful thing remains seeing a job the firm finished a year ago, rather than one it finished last week.

How we checked this

Facts in this piece were taken from the primary sources below and checked on 6 October 2026. Rules and figures change: check the source before you act on anything here.

• Companies House, GOV.UK: what Companies House does and find information about a company
• Health and Safety Executive: domestic gas safety, which names the Gas Safe Register as the register for gas engineers