You've nearly finished the job.
Then the customer asks:
“While you're here, could you just have a quick look at this?”
You take a look.
It seems straightforward.
Twenty minutes later, you've fixed it.
Then there's another thing.
And another.
By the end of the day, you've completed three jobs that weren't included in the original quote.
You add the additional work to the invoice.
The customer replies:
“I thought that was included.”
Neither side necessarily started with bad intentions.
The problem is that the work changed, but the agreement didn't change with it.
For tradespeople, variations and additional work are a normal part of the job. Buildings reveal unexpected problems. Customers change their minds. Specifications evolve. Extra tasks become convenient while you're already on site.
The danger begins when everyone assumes they understand what the change means.
A simple variation process can prevent a surprising number of disputes.
1. Know Exactly What Your Original Quote Covers
Managing additional work starts before the job begins.
If your original quote says:
Bathroom renovation — £6,500
there's plenty of room for disagreement.
Does that include decorating?
Waste removal?
Accessories?
Moving pipework?
Repairing unexpected damage?
Supply of fittings?
Making good elsewhere?
Now compare that with a quotation that clearly sets out the major work being supplied, relevant exclusions and assumptions.
The more clearly the original scope is defined, the easier it becomes to identify when something genuinely falls outside it.
You don't need a 40-page contract for every small domestic job.
But the customer should be able to understand what their agreed price is intended to buy.
2. Don't Let “Quick” Determine Whether Something Is Chargeable
Tradespeople often absorb small extras because:
“It only took five minutes.”
Occasionally doing something minor as goodwill can make perfectly good commercial sense.
The problem is when goodwill becomes the customer's expectation.
A five-minute task can involve:
Getting equipment out.
Finding materials.
Testing.
Cleaning up.
Accepting responsibility for another part of the property.
And interrupting the work you were actually scheduled to complete.
Whether you charge isn't determined solely by the number of minutes involved.
Decide deliberately whether something is:
Included.
Additional chargeable work.
Or a genuine goodwill gesture.
Don't accidentally create a fourth category:
Work you intended to charge for but never mentioned.
3. Stop Before You Start the Extra Work
This is perhaps the most useful habit.
The customer asks:
“Could you also fit this while you're here?”
Your instinct may be to immediately begin.
Instead, stop for thirty seconds.
Establish:
What they want.
Whether you can do it.
Whether it's within your competence and insurance.
Whether you have time.
Whether materials are required.
And whether there will be an additional charge.
The best time to discuss the price of extra work is before you've done it.
Afterwards, you're negotiating over something the customer has already received.
4. Say Clearly When Something Is Outside the Quote
You don't need to make the conversation confrontational.
Something as simple as:
“Yes, we can do that. It wasn't included in the original quote, though, so let me work out the additional cost before we go ahead.”
does several things immediately.
It confirms you're willing to help.
It establishes that the request is additional.
It tells the customer there may be a cost.
And it gives them an opportunity to decide.
That is considerably safer than:
“Yeah, no problem.”
followed by an unexpected £180 appearing on the invoice.
5. Agree the Additional Price Where You Reasonably Can
For straightforward extras, you may be able to provide a fixed additional price.
For example:
Additional socket requested: £X
or:
Additional preparation and painting to second wall: £X
Other work may contain more uncertainty.
Perhaps you've uncovered damage and don't yet know its full extent.
In that situation, you might agree:
An estimate.
A range.
An hourly or day rate.
Labour plus materials.
Or a staged investigation before further work is authorised.
The appropriate approach depends on the job.
What matters is that the customer understands how the additional cost will be determined.
6. Put the Variation in Writing
Verbal conversations are easily misunderstood.
You say:
“That'll probably be another £300.”
The customer remembers:
“He said it might cost up to £300.”
Two weeks later, neither person can prove exactly what was agreed.
Written confirmation doesn't have to be complicated.
For a relatively simple change, a message might record:
Additional work requested: replace damaged timber discovered beneath existing floor.Additional price: £420 including labour and materials.Effect on schedule: approximately one additional day.Please confirm you'd like us to proceed.
The customer replies:
“Yes, that's fine.”
Now both sides have a record.
For larger projects, a more formal variation procedure may be appropriate.
7. Record Changes Even When They Don't Affect the Price
Not every variation costs more.
The customer might change:
A finish.
Position.
Product.
Colour.
Layout.
Or another specification without materially affecting your cost.
Still record it.
Why?
Because six weeks later the customer may look at the finished project and say:
“That's not what was originally agreed.”
Technically, they're correct.
It changed.
Your record shows why.
Variations aren't only about collecting additional money.
They're about maintaining an accurate record of the project everyone ultimately agreed to.
8. Be Careful When the Customer Supplies Something Different
Imagine you've quoted to install a particular product.
The customer later buys something else.
Perhaps it's:
Larger.
Heavier.
More complicated.
Missing components.
Incompatible with the existing installation.
Or substantially more time-consuming to fit.
The customer may think:
“You're fitting one item either way, so why should the labour change?”
From your perspective, the work may now be completely different.
Address that before installation.
Explain what has changed and whether it affects:
Labour.
Materials.
Timescale.
Warranty responsibility.
Or suitability.
Don't wait until the invoice to reveal that their product choice increased the installation cost.
9. Treat Hidden Problems as Variations Too
Not every change originates with the customer.
Sometimes the building changes the job for you.
You remove flooring and find rotten timber.
Open a wall and discover something unexpected.
Remove an old fitting and uncover damage.
Begin preparation and find the substrate isn't suitable.
These situations need particularly clear communication because the customer didn't request the extra work.
Where practical, show them what you've found.
Take appropriate photographs.
Explain why it affects the original job.
Describe the options.
Then agree how to proceed.
Don't silently repair a substantial hidden defect and assume the customer will happily pay for it afterwards.
10. Explain the Effect on the Completion Date
A variation can change more than price.
The customer adds another day's work but still expects you to finish on Friday.
Meanwhile, you've already committed to another project starting Monday.
Now everybody is under pressure.
When agreeing additional work, consider whether it changes:
Completion date.
Material lead times.
Other scheduled trades.
Access requirements.
Drying or curing periods.
Your next booking.
Or the sequence of the project.
A £500 variation that requires three extra days is not simply a £500 conversation.
Time needs agreeing too.
Don't Let Lots of Tiny Extras Accumulate
This happens easily on larger jobs.
Monday:
“Can you just do this?”
Tuesday:
Another small request.
Wednesday:
Something else.
Individually, none seems worth stopping the project to discuss.
By Friday, you've completed £700 worth of additional work.
Now you have a problem.
Consider keeping a running variation record.
That could be as simple as:
Variation 01 — additional work — £X — approved 4 October
Variation 02 — specification change — £X — approved 6 October
Variation 03 — additional materials — £X — approved 7 October
Now both you and the customer can see how the original project has evolved.
Goodwill Should Still Be Identified as Goodwill
Sometimes you genuinely want to do something for free.
That's completely reasonable.
Perhaps the customer has given you a substantial project and asks for a tiny related task that takes a few minutes.
You decide:
I'll just do it.
Consider telling them.
For example:
“Normally we'd charge for that separately, but it's a small one, so I've taken care of it while we're here.”
Why mention it?
Because invisible goodwill has no perceived value.
The customer may simply assume it was always included.
Worse, they may expect the same thing next time.
Goodwill works better when both sides recognise it as goodwill.
Don't Agree to Extra Work You Shouldn't Be Doing
Being on site doesn't mean you should accept every request.
A customer may ask for something:
Outside your competence.
Outside your trade.
Outside your insurance.
Requiring another appropriately qualified person.
Requiring equipment you don't have.
Or carrying risks you don't want the business to accept.
“While you're here…” doesn't change any of those things.
It's perfectly professional to say:
“That's not something we undertake, so you'll need the appropriate trade for that.”
Turning down unsuitable work is better than accepting responsibility for something you shouldn't have touched.
What If the Customer Says, “I Thought It Was Included”?
Don't immediately turn the conversation into an argument.
Go back to the scope.
What does the quotation say?
Was the item discussed beforehand?
Is there correspondence about it?
Did something change during the project?
Could the original wording reasonably have caused confusion?
Sometimes the customer has misunderstood.
Sometimes the quote genuinely wasn't clear enough.
Sometimes you may discover that the work was reasonably part of what you originally agreed to provide.
Treat the documentation as evidence rather than assuming one side must automatically be wrong.
What If the Customer Refuses to Pay for an Approved Extra?
This is where your records become important.
If you can demonstrate:
What was requested.
What price was agreed.
When it was approved.
And that the work was completed...
...you are in a considerably stronger position than if the entire agreement consisted of a conversation nobody can now remember clearly.
For significant contractual or payment disputes, the appropriate next steps depend on the circumstances and the terms agreed. Businesses should obtain suitable professional or legal advice where necessary rather than assuming every dispute follows the same route.
Good documentation doesn't guarantee a dispute will never happen.
It can make the facts much easier to establish when one does.
Your Terms and Conditions Matter
For businesses regularly undertaking substantial work, appropriate written terms can help establish how changes are handled.
Depending on the nature of the work, they may address matters such as:
How variations are authorised.
How additional work is priced.
Payment arrangements.
Customer-requested changes.
Delays.
Materials.
Cancellation.
Access.
And dispute procedures.
Consumer-facing terms need to comply with applicable UK consumer law; simply writing something into your terms doesn't automatically make it fair or enforceable.
If you're creating contractual terms for significant work, professional legal advice can be worthwhile.
Remember Consumer Rights Still Apply
A variation process isn't a way to escape the obligations that already apply to the original work.
UK consumer law provides protections when consumers purchase services from traders, including requirements around how services are performed and circumstances where price or timing have not been fixed.
The exact legal position depends on the agreement and circumstances.
The practical lesson is straightforward:
Be clear about what you're agreeing to provide, what it costs and when that agreement changes.
If you're unsure about your obligations in a particular dispute, get appropriate advice rather than improvising your own interpretation of consumer law.
Build Variations Into Your Normal Workflow
The easiest variation system is one you'll actually use.
For a small business, the process might simply be:
1. Identify the change.
2. Explain why it's outside or changes the original scope.
3. Work out the price and time implications.
4. Send the customer written confirmation.
5. Get approval.
6. Complete the work.
7. Include the approved variation clearly on the final invoice.
That's it.
The process doesn't need to feel like a commercial construction contract every time somebody asks you to hang an additional door.
It just needs to scale appropriately with the value and significance of the change.
The Bigger the Change, the Better the Record Should Be
Adding a £15 component is not the same as adding £8,000 of work to a renovation.
Use common sense.
As the financial value, complexity and risk increase, so should the quality of the documentation.
A major change may require an updated quotation, revised scope, formal variation or amendment to the contract.
A tiny additional task might only require a clear message and approval.
The principle remains the same:
Don't leave significant changes undocumented.
“While You're Here” Can Be Good Business
Extra requests aren't inherently a nuisance.
They're often an opportunity.
The customer already trusts you.
You're already on site.
You may already have the necessary equipment.
Additional work can increase the value of the job without requiring another lead, quotation visit or separate journey.
Handled properly, everybody benefits.
The customer gets more work completed conveniently.
You generate additional revenue.
The problem isn't the phrase:
“While you're here…”
The problem is answering it without deciding what happens to the scope, price and schedule.
A thirty-second conversation before starting can prevent a thirty-message argument after finishing.
When the job changes, change the agreement with it—because the easiest extra work to get paid for is the work the customer clearly understood and approved before you did it.