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You only really protect yourself against mid-job price jumps before you start the job. After that, you're into persuasion and damage-limitation.
1. Who carries the risk now?
- On a fixed-price job with no special clauses, you're usually stuck with material price rises -- the risk sits with you, not the client.
- On time & materials / day rate or cost-plus, the client is already picking up actual material costs, so increases just flow through.
- Proper fluctuations clauses (common in JCT/NEC) let the contract sum move up or down if material or labour costs change, but on small jobs they're often deleted or never mentioned.
So if your quote and T&Cs say nothing about price movement, assume you're carrying most of the risk and need to negotiate.
2. What to do when prices jump mid-job
When the merchant rings with a nasty surprise after you've started:
Get the facts straight
Note old price vs new price, date of the increase, and which materials are affected. Work out the actual extra cost on this job, not just "everything's gone up".
Check your paperwork
Look at your quote and T&Cs: do you have anything in writing about price review, PC sums or fluctuations? If yes, follow that process. If no, you're asking for a variation by agreement, not enforcing a right.
Talk to the client early and calmly
Show them the numbers (supplier email/quote) and explain clearly:
"When I priced this, timber was £X. It's now £Y. On this job that's an extra £Z."
Offer options (see next section) rather than just "it costs more now".
Agree the change in writing
If they agree to a higher price or spec change, confirm it in an email/WhatsApp and adjust your paperwork. Treat it like any other variation -- updated quote line or variation order.
If they dig their heels in and you've no clause to lean on, you're into negotiation: decide whether you absorb it, meet halfway, or walk away from similar work next time.
3. Options you can put on the table
Instead of "I need more money", go in with choices:
Spec swap / value engineering
Offer alternative materials that are easier to get or haven't jumped as much (e.g. alternative brand, different finish) where regs allow it.
Pain-sharing
Split the extra: "The extra cost is about £1,000. If you cover £700, I'll absorb £300 so we can keep moving."
Scope tweak
Adjust the scope to keep the overall spend similar -- e.g. phase some nice-to-have bits to a later date.
Early ordering
For future jobs, agree to pre-order key materials on order acceptance to "freeze" the price, with the client covering deposits or storage.
Whatever you agree, write it down. "We'll sort it later" is how rows start.
4. How to protect yourself on the next job
The real win is changing how you quote and contract so you're not here again next year:
- Limit how long your quotes are valid -- e.g. "Valid for 30 days. Prices may be reviewed after this date based on supplier costs."
- Add a simple fluctuations / price review clause to your T&Cs and quotes (see plug-and-play clauses below).
- Use PC sums for volatile items (timber, steel, plasterboard, roofing sheets) -- make it clear the client pays the actual cost plus your agreed margin if it moves significantly.
- Consider contract type -- for very volatile periods or long jobs, consider cost-plus / time & materials, or fixed price with a limited fluctuations mechanism.
- Build sensible contingency into your rate -- don't be the cheapest if you know prices are moving weekly. A small buffer is cheaper than losing your shirt.
5. Things to avoid
- Locking in a rock-bottom fixed price on a long job with no wording about price movement.
- Promising "we'll hold this price for 6 months" to win the job when suppliers only hold theirs for 30 days.
- Not telling the client early when you see prices moving -- springing a big increase at the end of the job.
- Switching materials on the quiet to protect your margin -- you can fall foul of building regs, product safety and trust that way.
You're always better off having a grown-up chat, showing your workings, and agreeing a plan than trying to hide the problem.
Plug-and-play clauses
These are ready-to-use clauses you can bolt onto quotes and T&Cs. Tweak the numbers and wording to fit your business.
Clause 1 -- Quote validity (for the bottom of your quote)
Price validity
This quotation is based on material and labour costs at the date shown. It is valid for 30 days. If you accept the quotation after this period, we reserve the right to review the price to reflect any changes in supplier or labour costs before work starts.
Clause 2 -- Simple "price review if materials jump" (domestic-friendly)
Material price changes
Our prices are based on current supplier rates for key materials. If, before we order those materials, our cost price increases by more than [X]% compared to the prices used in this quotation, we will:
a) Show you evidence of the increase; and
b) Discuss and agree a fair adjustment to the contract price before proceeding.
If we cannot agree a revised price, either of us may choose not to go ahead with the affected part of the work, and you will only be liable for the reasonable costs we have already incurred.
Keep X realistic (e.g. 5-10%) so you're not trying to renegotiate over pennies.
Clause 3 -- PC sums / allowances (for volatile items)
Prime Cost (PC) sums and allowances
Any Prime Cost (PC) sums or allowances in this quotation are estimates only, based on typical current prices. The final amount you pay for these items will be:
a) The actual cost of the items you choose from our or our suppliers' ranges; plus
b) Our agreed handling/installation charges.
If the actual cost is higher or lower than the allowance, the difference will be added to or deducted from the contract price and shown as a variation.
Clause 4 -- Material availability and substitutions
Material availability and substitutions
If specified materials become unavailable or subject to excessive lead times after you accept our quotation, we will:
a) Inform you as soon as reasonably practicable;
b) Propose suitable alternative products; and
c) Agree any change in price and programme with you before ordering.
We will not substitute materials without your agreement, except where minor substitutions are necessary and do not affect performance, appearance or compliance with relevant standards.
Clause 5 -- Cost-plus / time & materials option (for bigger or volatile jobs)
Alternative pricing -- cost plus / time & materials
For projects where material prices are highly volatile or the scope is uncertain, we may offer to carry out the work on a cost-plus or time and materials basis instead of a fixed price. Under this arrangement you agree to pay:
a) Our labour at £[X] per hour/day;
b) The actual cost of materials, plant and subcontractors; plus
c) A management fee of [Y]% on those costs.
We will provide regular cost updates and a final breakdown showing time and materials used.
6. Who to contact
- Your merchants/suppliers -- ask about price-lock deals, bulk ordering, and advance ordering to fix prices on key materials.
- RICS -- guidance on fluctuations clauses and cost management: rics.org
- FMB -- practical guides on quoting and managing price risk: fmb.org.uk
- Your accountant -- to understand how price changes affect your margins and tax position.
7. Related guides on this site
- 8.5 Writing quotes that protect you
- 8.6 Terms and conditions template -- domestic work
- 8.7 Terms and conditions template -- commercial subcontracting
- 8.13 Pricing work -- day rate vs fixed price vs cost-plus
- 9.13 Scope creep -- client keeps adding work and expects it for free
- 2.5 Variation orders -- protecting yourself
Know someone who needs this?
Templates you might need
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