Summary

Telling a customer the price is going up is one of the most uncomfortable conversations in the trades, but how you handle it defines whether you keep the job, the relationship, and your reputation. The law is clear: if you gave a fixed quote, you are bound to that price for the agreed scope -- but you are equally entitled to charge for genuine additional work that falls outside that scope, provided the customer agrees to it before you do it. The key is speed, honesty, and documentation. Stop work as soon as you discover the problem, take photos, explain the situation in plain language, and put the revised cost in writing. Customers rarely object to paying more when they understand why -- they object when they feel blindsided by an inflated invoice after the fact.

Key Facts

  • A fixed quote is legally binding for the agreed scope of work. You cannot simply increase the price because the job took longer or cost more than you expected.
  • An estimate is not binding, but the final price must still be "reasonable" -- you cannot give an estimate of GBP 3,000 and invoice GBP 9,000 without clear justification.
  • Under the Consumer Rights Act 2015, services must be carried out with reasonable care and skill, at a reasonable price, and within a reasonable time.
  • A variation (also called a change order or extra works instruction) is the formal mechanism for agreeing additional costs. It should be agreed in writing before the extra work begins.
  • If you carry out extra work without the customer's agreement, you have no legal right to charge for it -- regardless of whether it was genuinely necessary.
  • Provisional sums in your original quote protect you. If you flagged an unknown (e.g., "provisional allowance of GBP 500 for drainage, subject to survey"), the customer has already accepted the price may vary in that area.
  • Most disputes over price increases come down to poor documentation -- verbal agreements turn into "he said, she said" situations that neither party can prove.
  • The FMB (Federation of Master Builders) contracts include standard variation clauses. If you use a written contract, the process for agreeing extras is already defined.

Common Scenarios

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Scenario Example How to Handle
Hidden damage Rotten joists under bathroom floor Stop work, document with photos, call customer, provide written variation before proceeding
Asbestos found Artex ceiling in pre-2000 property Stop work immediately, explain legal requirement for survey/removal, quote separately -- you cannot legally continue without a plan
Scope creep "While you're here, can you also..." Politely explain it is additional work outside the original quote, offer to price it separately
Material price increase Copper pipe price jump mid-job Reference your quote's validity period; if still within it, you absorb the cost; if expired, provide an updated price
Underestimated labour Job taking twice as long as expected If you quoted a fixed price, you bear the cost. For future jobs, build in more contingency or use provisional sums
Regulations require extra work Building Control requires fire stops you did not anticipate Explain the regulatory requirement, show the Building Control notice, and quote the additional work
Customer changes their mind "Actually, I want underfloor heating instead of radiators" Treat as a new specification -- issue a formal variation with revised price and any impact on the programme

Ready-to-Use Templates

Template 1: Discovering Hidden Problems (SMS)

Hi [Name], it's [Your Name] from [Company].

We've hit something unexpected at the property today. When we lifted the [bathroom floor / kitchen units / plasterboard], we found [describe problem -- e.g., rotten joists / corroded pipework / water damage to the subfloor].

I've taken some photos which I'll send over now.

This wasn't something we could have seen during the survey, and it needs sorting before we can carry on with the original work. I'll put together a price for the additional work and send it over today.

We've stopped work on that area for now so nothing gets worse. Happy to talk it through on the phone if that's easier -- just let me know.

Template 2: Formal Variation Notice (Email)

Subject: Variation Notice -- [Job Address / Quote Ref]

Dear [Customer Name],

Further to our conversation on [date], I am writing to confirm the additional work required at [property address].

ORIGINAL SCOPE (Quote Ref [XXX], dated [date]):
[Brief description of the original quoted work]

ADDITIONAL WORK REQUIRED:
During [describe stage of work], we discovered [describe the issue in plain language]. I have attached photographs showing the condition.

This additional work was not included in the original quotation because [it was not visible during the survey / it is behind the existing structure / it could not have been reasonably foreseen].

REVISED COSTS:

| Item | Description | Cost |
|------|-------------|------|
| Original quoted work | As per Quote Ref [XXX] | GBP [amount] |
| Additional work | [Description of extra work] | GBP [amount] |
| **Revised total** | | **GBP [amount]** |

[If applicable: The additional work will add approximately [X] days to the programme.]

Please confirm your agreement to this variation in writing (a reply to this email is fine) before we proceed with the additional work. If you would prefer not to go ahead with the extra work, please let me know and we can discuss your options.

I am happy to talk this through at any time.

Kind regards,
[Your Name]
[Company Name]
[Phone Number]

Template 3: Scope Creep Response (SMS)

Hi [Name], thanks for mentioning that -- happy to take a look.

Just so we're on the same page, that would be separate to the work we've already quoted for, so I'd need to price it up as an additional job. I don't want you getting a surprise on the invoice!

I can put a quick price together for you today / this week if you'd like? Then you can decide if you want us to crack on with it while we're here, or leave it for another time.

Template 4: Material Price Increase (Email)

Subject: Updated Quotation -- [Job Address / Quote Ref]

Dear [Customer Name],

I'm writing regarding Quote Ref [XXX] dated [original date] for [brief description of work] at [address].

When we originally quoted, the price was based on material costs at that time. The quote included a 30-day validity period, which has now passed.

Since then, the cost of [specific materials -- e.g., copper pipe / timber / cement] has increased by approximately [X]%. I wanted to let you know before we start rather than after.

The revised quotation is:

| Item | Original Price | Updated Price |
|------|---------------|---------------|
| Materials | GBP [amount] | GBP [amount] |
| Labour | GBP [amount] | GBP [amount] (unchanged) |
| **Total** | **GBP [amount]** | **GBP [amount]** |

I appreciate this is not the news you were hoping for, and I have absorbed as much of the increase as I can. The labour cost has not changed.

This updated quote is valid for 30 days from today. Please let me know if you would like to go ahead and I will get you booked in.

Kind regards,
[Your Name]
[Company Name]
[Phone Number]

Template 5: Customer Changes Specification (Email)

Subject: Variation to Specification -- [Job Address / Quote Ref]

Dear [Customer Name],

Thanks for letting me know you'd prefer [new specification -- e.g., underfloor heating instead of radiators / a different tile layout / an additional socket circuit].

I've priced up the change below. This replaces [specific section] of the original quote -- everything else stays the same.

VARIATION DETAILS:

| | Original Spec | Revised Spec |
|---|---|---|
| Description | [Original item] | [New item] |
| Materials | GBP [amount] | GBP [amount] |
| Labour | GBP [amount] | GBP [amount] |
| Net difference | | **GBP [+/- amount]** |

Revised total for the job: **GBP [amount]**

[If applicable: This change will add approximately [X] days to the programme, moving the expected completion date from [date] to [date].]

Please confirm you're happy to proceed and I'll update the schedule.

Kind regards,
[Your Name]
[Company Name]
[Phone Number]

Detailed Guidance

How do I document additional work?

Documentation is your insurance policy. If a dispute goes to Trading Standards, mediation, or court, the party with better records almost always wins.

The moment you discover additional work is needed:

  1. Stop work on the affected area. Do not proceed until you have agreement.
  2. Take photographs -- wide shots showing context and close-ups showing the detail. Include something for scale (a tape measure, your hand). Photograph the date on your phone screen if your camera does not embed metadata.
  3. Write a clear description of what you found, where it is, and why it affects the original scope. Use plain language the customer will understand -- "the floor joists under the bathroom are rotten and need replacing before we can tile" is better than "structural timbers compromised."
  4. Provide a written variation with the cost of the additional work, either as a separate line item or a revised total. Email is ideal because it is timestamped.
  5. Get written agreement before you proceed. A reply to your email or a text saying "go ahead" is sufficient -- it does not need to be a signed document, but written is always better than verbal.
  6. Keep a variation log if the job has multiple changes. A simple spreadsheet with the date, description, agreed cost, and customer confirmation reference is enough.

Using squote: Variation quotes raised in squote are sent by email as a PDF and stored alongside the original quote -- so every agreed price change is documented, timestamped, and permanently on record without any extra admin.

What are my legal obligations?

Consumer Rights Act 2015:

The Act applies to all contracts between a trader and a consumer (i.e., most domestic work). Key provisions:

  • Section 49: Services must be performed with reasonable care and skill.
  • Section 51: If no price was agreed, the consumer pays a reasonable price and no more.
  • Section 52: If no timeframe was agreed, the service must be completed within a reasonable time.

Quotes vs estimates:

  • A quote is a fixed-price offer. Once accepted, it forms a binding contract for that price. You cannot increase it unilaterally -- you need the customer's agreement to a variation.
  • An estimate gives you more flexibility, but the final price must still be reasonable relative to the estimate. A 10-15% overrun on an estimate is generally considered acceptable; doubling the price is not.

When can you charge more than the original quote?

You can charge more only when:

  • The customer requests additional work outside the original scope (and agrees to the additional cost).
  • You discover genuinely unforeseeable work that was not visible or reasonably discoverable during your initial survey -- and the customer agrees to the cost before you do it.
  • Your quote included provisional sums, and the actual cost of those items differs from the allowance.

You cannot charge more simply because:

  • The job took longer than expected.
  • You underpriced it.
  • Your subcontractor charged you more.
  • Material costs rose within your quote's validity period.

Supply of Goods and Services Act 1982:

This older Act (largely supplemented by the Consumer Rights Act 2015 for consumer contracts) still applies to business-to-business work. It implies similar terms: reasonable care and skill, reasonable time, and reasonable price.

How do I prevent price increase disputes?

The best time to prevent a dispute about extras is before you issue the original quote.

1. Do a thorough site survey

Spend the time. Lift inspection hatches, check behind access panels, look in the loft, check the consumer unit. The more you see before quoting, the fewer surprises there are during the job. If you cannot inspect something (e.g., behind a fitted kitchen, under a concrete floor), say so in the quote.

2. Write clear exclusions

State explicitly what is NOT included. For example:

  • "This quote excludes any remedial work to existing plumbing / wiring / structure."
  • "This quote does not include making good to areas outside the immediate work zone."
  • "Asbestos survey and removal, if required, is not included."
  • "This quote assumes standard soil conditions. Any additional excavation required due to rock, clay, or contaminated ground will be quoted separately."

3. Use provisional sums for unknowns

If there is a genuine unknown, include a provisional allowance rather than guessing:

  • "Provisional sum of GBP 400 for drainage connection -- to be confirmed once existing drain is exposed."
  • "Provisional allowance of GBP 600 for subfloor preparation -- actual cost subject to condition found."

This sets the customer's expectation that the final cost may vary in that specific area, and gives you a contractual mechanism to adjust it.

4. Set a validity period

Always include a validity period on your quote (30 days is standard). This protects you against material price fluctuations on jobs that take weeks or months to confirm.

5. Use a written contract on larger jobs

For anything over about GBP 5,000, use a proper contract. The FMB contract templates are written in plain English and include standard variation clauses. The JCT Minor Works contract is appropriate for larger domestic projects. These contracts define how variations are instructed, valued, and agreed -- which takes the awkwardness out of the conversation.

What if the customer refuses to pay for additional work?

This is the scenario every tradesperson dreads. Here are your options:

If you have written agreement to the variation:

You have a clear contractual right to payment. Follow your standard payment terms. If the customer does not pay, you can pursue it through the courts like any other debt. Your documentation (photos, variation notice, customer's written agreement) is your evidence.

If you did the work without written agreement:

This is much harder. You may be able to claim on the basis of "quantum meruit" (a reasonable sum for work done), but the customer's position is strong -- they can argue they never agreed to the additional cost. This is exactly why you should never proceed without agreement.

If the customer disputes the need for the work:

Offer to get a third-party opinion. An independent surveyor, building inspector, or relevant trade body can assess whether the work was genuinely necessary. If it was, most reasonable customers will accept this.

If agreement cannot be reached:

  • Negotiate: Offer to split the difference, or agree a reduced rate for the additional work. Preserving the relationship and getting most of your money is usually better than winning 100% of a disputed amount.
  • Mediation: Many trade bodies (FMB, TrustMark, Which? Trusted Traders) offer dispute resolution services. This is cheaper and faster than court.
  • Small claims court: For amounts up to GBP 10,000 in England and Wales, you can apply online at money claims online (MCOL). Court fees are modest and can be claimed back from the debtor.

What you should NOT do:

  • Do not refuse to complete the originally quoted work as leverage. This puts you in breach of your original contract.
  • Do not remove work already done. This is almost certainly illegal (Criminal Damage Act 1971, if it is the customer's property).
  • Do not withhold certificates, test results, or compliance documents. You have a professional and often legal obligation to provide these.

Frequently Asked Questions

Can I walk off a job if the customer will not agree to pay for extras?

You can stop the additional work, but you must complete the original quoted work (or reach a mutual agreement to end the contract). Walking off entirely puts you in breach of contract, and the customer could claim the cost of getting someone else to finish the job -- often at a higher price than your quote. If you genuinely cannot complete the original work without the additional work being done first (e.g., rotten joists must be replaced before you can tile the floor), explain this clearly in writing and give the customer the option to instruct the additional work or terminate the contract by mutual agreement.

Do I need a formal contract to claim for variations?

No. A contract does not need to be a formal document -- an exchange of emails, text messages, or even a verbal agreement can form a binding contract. However, written evidence is always stronger. At a minimum, send a text or email describing the additional work and cost, and get a reply confirming agreement before you start.

What if the customer says "just do whatever needs doing"?

This feels like blanket approval, but it is not. "Whatever needs doing" is vague and will not protect you if the customer later disputes the cost. Always follow up with a specific description and price in writing: "Just to confirm, the additional work is [X] and the cost will be GBP [Y]. Can you confirm you're happy to proceed?" A text reply saying "yes" is enough.

How much can the final price exceed an estimate before it becomes unreasonable?

There is no fixed legal threshold, but as a rule of thumb, an overrun of up to 10-15% on an estimate is generally considered acceptable. Beyond that, you should have contacted the customer to discuss the increase before continuing. An overrun of 50% or more without prior agreement is almost certainly going to be challenged, and Trading Standards is likely to side with the customer.

Should I charge for the time I spend investigating unexpected problems?

This is a judgement call. On a large job, the investigation time is usually absorbed as part of the project. On a small job where the investigation is a significant proportion of the total work, you may want to flag it. Be upfront: "I need to spend [X time] investigating before I can give you a price for the fix -- is that OK?" Most customers will agree if you explain why.

Regulations & Standards