What Is Professional Indemnity Insurance for Tradesmen?
Professional indemnity insurance pays a client’s financial loss when your advice, design or specification turns out to be wrong. It also pays the cost of defending the allegation, whether or not it is eventually proved.
Most trade policies answer for broken things and injured people. Professional indemnity answers for a different kind of damage: money the client lost because they relied on what you told them.
This guide covers what the policy pays, how the claims-made trigger works, what the retroactive date does and where design liability comes from.
Professional indemnity is a claims-made policy, so it’s the policy running when a claim arrives that pays out, not the one that was live when you gave the advice. That’s why you need continuous cover and, if you ever stop trading or change insurer, run-off cover to protect advice you gave in the past. Check your retroactive date matches how long you’ve been trading, or older work won’t be covered at all.
Get a professional indemnity quote and cover the advice you give clients.
- What does professional indemnity actually pay for?
- What counts as professional advice for a trade?
- How does a claims-made policy work?
- What is the retroactive date and why does it matter?
- Where does design and specification liability come from?
- How does it sit next to public liability?
- What does a professional indemnity policy exclude?
- What is run-off cover and when do you need it?
- Frequently asked questions (FAQs)
What does professional indemnity actually pay for?
It pays damages for pure financial loss caused by professional negligence, together with the legal costs of defending the claim, up to the limit on your schedule.
Financial loss, not broken glass
Pure financial loss means money lost with nothing physically damaged. A heating system sized too small still works, it just costs the client a fortune to run and has to be replaced.
No window is broken and nobody is hurt, so there is nothing for a liability policy to attach to. That is the gap professional indemnity fills.
Defence costs are the part trades underestimate
Defending a design allegation means solicitors, an expert witness and often a second expert to answer the first. Those bills start the day the letter arrives.
Most trade wordings pay defence costs even where the claim collapses. Without cover you pay them yourself and get nothing back.
What a claim looks like on a trade job
An electrician specifies a distribution board that cannot take the client’s later machinery load. The install is faultless, the specification is not.
A professional indemnity claim usually contains four things:
- The client relied on something you designed, specified or advised
- What you told them fell short of reasonable skill and care
- They lost money as a result, often on remedial or redesign work
- They are now asking you to pay for it
What counts as professional advice for a trade?
Anything a client relies on to make a decision. The moment you choose the size, the route, the material or the method for them, you are advising rather than installing.
Advising versus installing
A plumber fitting a boiler an architect specified is installing. The same plumber choosing the boiler, sizing the flow and setting out the pipework is advising.
The physical work is identical in both cases. The liability is not, because only one of them puts your judgement on the line.
The quote that turns into a specification
Trade quotes routinely list model numbers, cable sizes, joist centres and insulation values. Once the client signs it, that quote is the specification.
If any of those choices was yours and turns out to be wrong for the building, the loss is a professional one. Nobody had to call you a consultant for that to happen.
Written reports and sign-offs
Condition reports, damp surveys, heat loss calculations and pre-purchase opinions are advice in its purest form. So is an email telling a client the existing wiring is fine to keep.
Anything you put in writing can be produced years later by a solicitor. Keeping copies of what you actually said is your best defence.
How does a claims-made policy work?
Professional indemnity responds to the policy in force when the claim is made against you, not the policy that was running when you did the work.
Occurrence cover versus claims-made
Public liability and employers’ liability are occurrence policies. The year the accident happened is the year that pays, even if you left that insurer a decade ago.
Professional indemnity flips that. Today’s policy handles today’s letter of claim, about work you may have finished four years back.
Why a gap in cover leaves you bare
Let the policy lapse and there is nothing in force when the claim arrives. The old insurer has no obligation and there is no new insurer yet.
Continuous cover is the whole point of the product. Premiums are an allowable business expense, and HMRC names professional indemnity among the insurance costs a self-employed trade can set against profits.
| Claims-made (professional indemnity) | Occurrence (public and employers’ liability) | |
| What triggers cover | The claim being made against you | The incident happening |
| Which policy answers | The one running when the claim arrives | The one running when the damage occurred |
| Effect of a lapse | Old work becomes uninsured | Old work stays covered by the old policy |
| Cover after you stop trading | Needs run-off cover | Continues automatically |
| Date that limits old work | The retroactive date | Not applicable |
What is the retroactive date and why does it matter?
The retroactive date is the earliest date of work your policy will look at. Anything you designed or advised on before it falls outside the cover, however recent the claim.
The date that governs old work
A policy with a retroactive date of 2022 answers claims about work carried out from 2022 onwards. A claim about a 2019 drawing is declined even though the policy is live.
Check the schedule for that date before you renew anything. It is one line, and it decides how much of your working history is protected.
Keeping continuity when you switch insurer
Moving insurer is fine as long as the new policy carries the original retroactive date forward. Ask for that in writing rather than assuming it.
A cheaper quote with a fresh retroactive date is not the same product. Check the insurer on the FCA Register while you are at it, so you know who is actually carrying the risk.
Why this is not the same as backdating
Insurance cannot be backdated. You can never buy cover today for a problem you already know about, and no insurer will let you.
A retroactive date does something different. It lets a live policy consider work done before inception, provided nothing had gone wrong at the point you bought it.
Where does design and specification liability come from?
It comes from the contract you signed and the duty the law attaches to giving advice. Design and build contracts move that duty from the architect onto the trade.
Design and build puts you in the designer’s chair
On a design and build job the builder takes responsibility for the design as well as the construction. That is a professional duty, not a workmanship one.
Subcontractors picking up portions of design carry the same exposure. Mechanical, electrical and structural packages are the usual candidates.
Main contractors know this, which is why their subcontract terms ask for the cover by name. The requirement usually appears alongside the public liability limit.
Reasonable skill and care versus fitness for purpose
Professional indemnity policies insure a duty of reasonable skill and care. That is the standard a competent professional would meet.
Contracts sometimes demand fitness for purpose instead, which guarantees a result. Insurers rarely cover that heightened duty, so signing up to it can leave you uninsured.
Designer duties under cdm 2015
Anyone who prepares or modifies a design is a designer under CDM 2015, and those rules reach domestic work as well as commercial projects.
Being a designer under CDM does not create a professional indemnity claim on its own. It does show how easily a trade slips into a design role without noticing.
How does it sit next to public liability?
Public liability answers injury and property damage. Professional indemnity answers money lost through advice, and neither one covers the other’s territory.
The same job, two different losses
Drop a radiator through a client’s floorboards and that is a public liability claim. Specify the wrong radiator and leave the room cold, and no property was damaged at all.
The second loss is money, not matter. Insurers draw the line there because the two risks price completely differently.
When one incident triggers both
A badly specified flue can cause physical damage and a redesign bill in the same event. Insurers then split the claim between the two policies.
Holding both with one insurer makes that argument shorter. It is one of the better reasons to buy a package rather than assemble covers separately.
| What went wrong | Which policy answers | Why |
| Your ladder cracks a client’s conservatory roof | Public liability | Physical damage to third-party property |
| A visitor trips on your trailing lead | Public liability | Third-party injury on site |
| Your heat loss calculation undersizes the boiler | Professional indemnity | Financial loss from a design error |
| You specify cladding that fails building control | Professional indemnity | Remedial cost caused by your specification |
| Your apprentice falls from a hop-up | Employers’ liability | Injury to someone who works for you |
| You fit the boiler badly and it has to be redone | Neither | Putting right your own workmanship is your cost |
What does a professional indemnity policy exclude?
Your own bad workmanship, anything you already knew about, deliberate acts and most contractual guarantees all sit outside the cover.
Bad workmanship is not a design claim
A crooked run of pipe is a workmanship problem, and putting it right is a cost you carry. The policy is not a warranty on the quality of your hands.
The dividing line is whether the decision or the execution failed. Wrong choice is professional, sloppy fitting is not.
Known circumstances and deliberate acts
You have to declare anything you already know could turn into a claim. Buying a policy over a brewing dispute gets that dispute excluded.
Fraud, dishonesty and deliberate breaches are excluded across the market. So is anything you knew was wrong at the time you did it.
Fines, penalties and guarantees
Regulatory fines and penalties are not insurable losses in the UK. Neither are liquidated damages you agreed to in a contract without your insurer knowing.
Read the exclusions the same way you would read the tools section of a trade policy. The refusals happen there rather than in the headline cover.
What is run-off cover and when do you need it?
Run-off cover keeps a claims-made policy alive after you stop trading, so late claims about old work still have somewhere to land.
Retiring, selling or closing down
Cancel your last policy and your protection ends the same day. Every design you ever signed off becomes your personal problem from then on.
Run-off is bought as a continuation of the existing policy, keeping the retroactive date intact. It costs less than a trading policy because no new work is being added.
How long to run it for
Most trades keep run-off going for several years after the last job, because design faults take time to show up. Six years is a common benchmark, matching the usual contract limitation period.
Contracts and collateral warranties sometimes fix the period for you. Check what you signed before you decide when to stop paying.
What to check before you cancel
Confirm the retroactive date, the limit and whether defence costs sit inside or outside it. Those three lines decide what the run-off is actually worth.
You get a 14 day cooling-off period on general insurance under FCA rules, so there is time to read the wording properly. Insurance premium tax of 12% is already inside the price you are quoted.
Frequently Asked Questions (FAQs)
Financial loss a client suffers because your advice, design or specification was wrong, plus the legal costs of defending the allegation.
Public liability covers injury and physical damage. Professional indemnity covers money lost through professional error, where nothing has been broken and nobody hurt.
The policy in force when the claim is made is the one that responds, rather than the policy you held when the work was done. Continuous cover therefore matters.
The earliest date of work your policy will consider. Work carried out before it is outside the cover, so keep the original date when you change insurer.
No. Cover starts when the policy incepts, and a retroactive date is a different mechanism that only works while nothing has already gone wrong.
No. Redoing work you fitted badly is your own cost, and damage that work causes to other property sits with public liability instead.
If you ever gave design or specification advice, yes. Without it, a claim arriving after you close has no policy to attach to.
Usually. Policies insure reasonable skill and care, so accepting a guarantee of the finished result can put the obligation outside your cover.
Business insurance bought wholly and exclusively for the trade is an allowable expense, and HMRC names professional indemnity specifically.