Workmanship warranties explained

First: what a workmanship warranty is not

It is not the same as a product guarantee. If a boiler fails, the manufacturer's warranty covers the boiler; your workmanship warranty covers the way it was installed. Customers often mix the two up, so say plainly on your paperwork which one applies to which part of the job.

It is also not a substitute for your customer's legal rights. Section 49 of the Consumer Rights Act 2015 requires that a service is performed with reasonable care and skill. Whatever you write on a warranty card, that obligation stands, and you cannot write it away.

The types of workmanship warranty

Most UK trades fall into one or more of these five categories:

1. Statutory rights (the minimum, always there)

For consumer work the law already gives customers a remedy if the work is faulty: repeat performance or a price reduction under the Consumer Rights Act. It costs you nothing to offer and nothing to print — a line like "Your statutory rights are not affected" is honest and expected. Coverage: any work done without reasonable care and skill. Limit: it is not a fixed-term promise, and the practical window depends on the nature of the defect and the six-year limitation period for contract claims in England and Wales.

2. A goodwill workmanship guarantee (the common 12 months)

The standard trade practice: "All work guaranteed for 12 months." It is a goodwill promise, so you decide the length, the scope and the conditions. Coverage: you return and put right defects in your own work, usually labour only. Limit: it typically excludes the materials, fair wear and tear, misuse, and anything caused by someone else's work after you finished.

3. A written warranty with defined terms (the professional version)

The same promise, written with real detail: how long, what counts as a defect, how the customer reports one, and what you will do about it. This is the version that avoids arguments, because both sides know the deal before work starts. See the lists below for what to include and exclude.

4. Insurance-backed guarantees (IBGs)

An insurance-backed guarantee does two things a personal promise cannot: it survives your business ceasing to trade, and it can extend cover beyond the period you would comfortably offer yourself. They are common in roofing, double glazing, kitchens and bathrooms, usually arranged through the scheme your trade body or certification body runs. Coverage: typically defects in the covered work for the scheme's stated term, honoured even if the installer has stopped trading. Limit: they cost money per job, have registration deadlines, and exclude whatever the scheme's own terms exclude — read the scheme document before you promise anything on its behalf.

5. Trade-body and certification schemes

Bodies such as TrustMark (the government-endorsed quality mark), gas and electrical registration schemes and trade associations set standards and often require members to offer certain guarantees or hold insurance. Joining one does not create the warranty for you, but it does give customers a route to complain if you will not put something right, which is worth knowing before you sign up.

What a written workmanship warranty typically includes

• The exact work covered — ideally the job reference or invoice number, not "all work".
• The length of cover, with a start date (usually completion or final payment).
• What you will do: return to inspect and rectify defects in the workmanship, at no charge.
• Whether materials are included or referred back to the manufacturer's guarantee.
• How to claim: who to contact, and that the customer should report a defect promptly.
• That the customer allows reasonable access to inspect and repair.
• A note that statutory rights are unaffected.

What a workmanship warranty does not cover

• Fair wear and tear, or damage from misuse, neglect or attempted DIY repair by others.
• Defects in customer-supplied materials, and faults in products covered by the maker's own guarantee.
• Damage or faults caused by a third party working on the site after you finished.
• Changes the customer makes to the work, or work altered by another tradesperson.
• Weather damage, flood, subsidence and similar events outside your control.
• Cosmetic preferences — a finish that meets the specification but not the customer's taste.
• Consequential costs: hotel stays, lost earnings, storage, or the cost of hiring someone else.
• Anything you did not quote for, or work added later without agreement.

Be careful how you word exclusions. You cannot exclude liability for work done without reasonable care and skill in consumer jobs, and vague catch-alls such as "no liability whatsoever" are unenforceable and erode trust. Specific exclusions, honestly worded, do the job.

Writing your own: the short version

Put the warranty on the quote, not after the job: duration, what is covered, what is not, and how to claim. Keep it consistent across jobs so you are not inventing terms each time, and keep a copy with the invoice so the promise and the paperwork travel together. If a job involves registered installations — gas, electrics, glazing — file the certificate and register any manufacturer warranty promptly, because some extended warranties only activate once registered.