SiteKiln gives you plain-English information, not legal advice. It's aimed at small UK construction businesses. Laws change and every job is different, so speak to a solicitor or adviser before you rely on this for a real dispute.
Doing work for mates and family runs on feelings instead of paperwork -- until it goes wrong and suddenly everyone remembers things differently.
1. The short version
Legally, it's still a contract like any other (texts, WhatsApps and "yeah go on then" messages can all add up to a binding deal), and the same rules on quality, payment and disputes apply -- you just have a lot more to lose personally if it blows up.
2. Where you stand legally
- If you agree to do work, they agree to pay, and you crack on, that's usually a binding contract whether or not you ever shuffled a formal document under their nose.
- Courts look at what was actually said and done, not how friendly it felt at the time:
- Offer, acceptance, price (or a way to work it out) and intention to create legal relations.
- WhatsApps like "Is it my job then?" / "Yes mate, crack on" have already been treated as forming contracts in real construction cases.
- The same legal duties apply as for any domestic client:
- Reasonable care and skill under the Consumer Rights Act.
- Building regs, safety, party wall rules etc. still bite -- "it's only for my cousin" isn't a defence.
- If it goes wrong:
- They can complain, use Citizens Advice templates, and ultimately sue you like any other builder.
- You can chase them for unpaid money in exactly the same way (pre-action letter, small claims).
So from the law's point of view, "mate's rates" is just a discount contract, not a different set of rules.
3. Where these jobs go wrong in real life
The patterns are boringly consistent:
Vague scope
"Sort the kitchen out" turns into new electrics, extra units, plastering the hall and half the garden. No one wrote down what was actually agreed.
Woolly price / freebie creep
You say "I'll look after you", they hear "it'll be cheap / free". Extras get thrown in "as a favour", then resented.
No dates, no priority
You squeeze them in between paying work. They expect priority because "we're family", and feel mugged off when you don't turn up.
No clear line between "trade" and "helping out"
You think you're doing mate's rates, they think they're helping you out by "giving you the work", and both feel owed.
When it goes sour, everyone starts digging back through messages and stories trying to reconstruct a contract that never made it onto paper.
4. How to set it up so you don't fall out
You don't need a 30-page JCT with your brother-in-law, but you do need some formality.
Treat them like any other client on the basics
- Written scope -- what rooms, what's included, what isn't.
- A clear price, or day rate and rough hours.
- Payment terms -- deposit, stages, when final payment is due.
Put "mates rates" in black and white
- Show the "normal" price and the discounted price so they can see what they're getting.
- Make clear it's still a paid job, not open-ended favours.
Agree where it sits on your priority list
- "This is a paid job but it will be fitted between existing bookings, so dates may move."
- Or: "Full-price, normal priority, treated exactly like any other client."
Stay off cash-only handshakes
- Use invoices and bank transfer like normal; it protects both of you if anyone questions what was agreed.
This feels a bit stiff when you're sat at their kitchen table, but it's infinitely kinder than a Christmas-dinner fallout later.
5. What to do when it's already gone wrong
If you're already in choppy water:
Get everything in writing now
- Send a calm message summarising what you believe was agreed on scope, price and timing.
- Ask them to reply with anything they think is different.
Separate
- Legit issues (snags, delays, missed bits).
- From friendship noise ("we thought you'd just do XYZ because we're mates").
Treat the legit stuff like any other job
- Offer to put genuine defects right.
- Explain calmly where you think extra money is due for scope creep.
Decide your line
- What you're willing to swallow to keep the relationship.
- What you're not willing to do (e.g. full refund when the work is basically fine).
If you can, aim for a simple, written draw-a-line-under-it deal -- a small discount or bit of extra work in exchange for them treating matters as settled.
6. Common mistakes
- Not writing anything down because "it feels weird" -- every construction lawyer and judge will tell you: informal agreements are the ones that end up in court most often.
- Over-promising to keep the peace -- saying "I'll do it cheap, whenever you want, and we'll sort the rest later" sounds nice and gives you zero protection.
- Letting them skip the queue -- pushing paid clients aside for a mate's job is how you annoy everyone and blow up your cashflow.
- Being either a doormat or a rottweiler -- giving away thousands of pounds of work "because it's family" breeds resentment; treating them harsher than a normal client because you're angry breaks the relationship.
- Using informal messages as a comfort blanket -- WhatsApps and DMs can be contracts; don't assume "it was only a chat" lets you wriggle out if things turn formal.
7. Who to contact
- Citizens Advice -- basic consumer rights and dispute options, exactly what your friend or relative will be looking at: 0800 144 8848 (free)
- Mediation services -- local mediation can help if the personal relationship matters more than squeezing every penny (varies)
- Solicitor with construction / contract experience -- if a friend/family job has turned into a genuine legal threat or large money dispute (paid)
8. Sources and legislation
- Consumer Rights Act 2015 -- Part 1, Chapter 4 (services: reasonable care and skill, remedies). Same duties apply whether the client is a stranger or your sister-in-law. legislation.gov.uk/ukpga/2015/15
- Contract formation -- offer, acceptance, consideration and intention to create legal relations. Informal agreements (texts, WhatsApps, verbal) can form binding contracts. See RTS Flexible Systems Ltd v Molkerei Alois Müller GmbH [2010] UKSC 14 on contract formation from conduct.
- Building Regulations 2010 -- compliance required regardless of who the client is. legislation.gov.uk/uksi/2010/2214
- Citizens Advice -- "Before you get work done on your home" guidance: citizensadvice.org.uk
9. Related guides on this site
- 9.1 Customer won't pay the final invoice
- 9.2 Customer claims defective work
- 9.3 Customer changed their mind mid-job
- 9.6 Customer agreed a resolution then went back on it
- 9.13 Scope creep -- client keeps adding work and expects it for free
- 8.5 Writing quotes that protect you
- 8.6 Terms and conditions template -- domestic work
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