Co-buying means two or more people purchase a home together, sharing the deposit, the mortgage and legal ownership of the property. It usually suits friends, siblings or small groups who can't afford to buy alone but can pool resources to get on the property ladder. The upside is straightforward: a smaller deposit each, shared bills, and a faster route to ownership. The downside is just as real. You take on shared liability for the mortgage and the risk of disputes if someone wants out. HM Land Registry records how you own the property, and a Declaration of Trust protects what happens if things change. Platforms like CoHaus now exist specifically to manage that risk.
Quick verdict:
- Best for: people with steady income who trust their co-buyers and want a documented, fair arrangement
- Watch out for: informal agreements, unequal contributions left unrecorded, and no exit plan
Survey data suggests roughly half of prospective buyers would consider co-purchasing with friends or family to afford a home. That's not a niche idea anymore. It's a mainstream response to a market that has priced many people out of buying solo.
Key Takeaways
Co-buying gives prospective homeowners a realistic route to ownership, but only holds up long-term when beneficial shares, liability and exit terms are documented in a Declaration of Trust before exchange.
| Point | Details |
|---|---|
| Choose ownership type deliberately | Pick tenants in common over joint tenants whenever contributions are unequal. |
| Expect joint and several liability | Lenders can chase any co-buyer for the full mortgage if others default. |
| Get a Declaration of Trust | This document records shares and exit terms, and is what courts will consult in a dispute. |
| Plan the exit before you buy | Agree sale triggers, notice periods and buy-out formulas in advance. |
| Consider a structured platform | Cohaus pairs community matching with legal protections and transparent exit terms to reduce common co-buying risks. |
Table of Contents
- How co-buying works: joint tenants vs tenants in common
- Deposits, mortgages and the lender reality for co-buyers
- The legal documents that actually prevent disputes
- What goes wrong, and how courts get involved
- How to start: a practical checklist
- How Cohaus reduces the risks of co-buying
- When co-buying makes sense, and when it doesn't
- Get started with Cohaus
- Primary sources and further reading
- Sources
How co-buying works: joint tenants vs tenants in common
When you buy with someone else, you choose how the property is legally held. This decision affects inheritance, control and what happens if the relationship sours.
- Joint tenants: you own the whole property together, equally, with automatic right of survivorship. If one owner dies, their share passes to the other owner, not through a will.
- Tenants in common: you own defined, potentially unequal shares, and each share can be left to whoever you choose in a will.
HM Land Registry requires you to declare which structure applies when the property is registered, and you can switch later through a formal process. Most co-buyers who contribute unequal amounts choose tenants in common, because it lets the legal title reflect the real financial split rather than defaulting to a 50/50 assumption.
This is also where legal title and beneficial interest diverge. The names on the mortgage and title don't automatically dictate who gets what money back when the house sells. That has to be recorded separately.
Co-buying is not the same as Shared Ownership, where you buy a share from a housing provider and pay rent on the rest. Co-buying is a private arrangement between individuals; Shared Ownership is a government-backed scheme with its own rules on staircasing and restrictions. For a fuller comparison of the two ownership structures, see our guide on tenants in common vs joint tenancy.
Pro Tip: If your contributions to the deposit aren't equal, choose tenants in common from day one. Retrofitting the paperwork later is far more expensive than getting it right at the start.
Deposits, mortgages and the lender reality for co-buyers
Most lenders require every co-buyer to be named on the mortgage, and that comes with joint and several liability: the bank can chase any one of you for the full outstanding balance if the others stop paying. It doesn't matter what you and your co-buyers privately agreed about who pays what.
Say three friends buy together and one loses their job. The lender doesn't split the shortfall three ways and wait patiently. It can pursue whichever borrower is easiest to recover from, for the entire debt, leaving that person to chase the others separately.
That's why unequal contributions need to be documented properly rather than left as a verbal understanding.
- Record contribution splits in a Declaration of Trust, not a text message or a memory
- Get an Agreement in Principle before you view properties, so everyone knows their real borrowing capacity
- Check how a joint mortgage affects each person's ability to borrow again later, since it appears on your credit file even after you've sold your share
Our guide to joint and several liability mortgages covers how lenders actually behave when payments are missed.
The legal documents that actually prevent disputes
A Declaration of Trust (sometimes called a Deed of Trust) is the single most important document in co-buying. It records each person's beneficial share, how the deposit was split, what happens to the property if someone wants to sell, and how proceeds get divided. Legal guides consistently recommend it, particularly whenever contributions aren't equal.
- Instruct a solicitor before you exchange, not after a disagreement starts.
- Draft the Declaration of Trust alongside the conveyancing, covering shares, exit terms and what happens on default.
- Update your will to reflect the co-ownership. This matters even more if you're joint tenants, since survivorship overrides whatever your will says about that property.
- Confirm the beneficial split is registered in a way a court would actually recognise if it came to that.
Pro Tip: Ask your solicitor one direct question: "If we fell out tomorrow, what does this document say happens next?" If they can't answer clearly, the deed isn't finished.
What goes wrong, and how courts get involved
Disputes tend to follow a familiar pattern: one co-buyer stops paying, someone wants to sell while the others don't, or a relationship breaks down and living together becomes untenable.
Without a written agreement, courts can step in under the Trusts of Land and Appointment of Trustees Act 1996, ordering a sale or ruling on beneficial shares. Judges may also apply equitable accounting, adjusting the final split to reflect who actually paid for what and who lived in the property, and for how long.
Informal arrangements fail in court far more often than people expect, and litigation is expensive for everyone involved.
- Agree exit rules before you buy, not after a dispute starts
- Consider life insurance to cover a co-buyer's share of the mortgage
- Set clear rules for what happens if one person wants to rent out their share or stop living there
How to start: a practical checklist
- Talk about money first. Agree contribution shares, monthly payments, and who covers what bills, before you look at a single property.
- Get an Agreement in Principle. This confirms what you can genuinely borrow together and flags any credit issues early.
- Instruct a solicitor early and start drafting the Declaration of Trust in parallel with the property search, rather than treating it as an afterthought.
- Agree exit terms, insurance and a dispute process before you exchange. Decide now what happens if someone wants to sell in two years.
Pro Tip: Put a timeline on the exit clause. "Either party can request a sale after 12 months' notice" is far easier to enforce than an open-ended promise to "sort it out later".
Our guide to arranging a joint mortgage with friends walks through the lender conversation in more detail.
How Cohaus reduces the risks of co-buying
Cohaus was built around the exact failure points described above: unclear shares, no exit plan, and mismatched expectations between people who trust each other but have never bought property together.
- Community matching helps you find co-buyers whose finances and goals actually align with yours, rather than relying on whoever happens to be available
- Shared deposit management keeps contributions transparent from the start
- Legal protections, including Declaration of Trust support, are built into the process rather than bolted on afterwards
- Transparent exit terms are agreed upfront, so nobody is negotiating from scratch mid-dispute
Given that roughly half of buyers say they'd consider co-purchasing to reach the property ladder, the gap isn't appetite. It's structure. Cohaus's full library of co-buying guides covers the detail behind each of these features.
When co-buying makes sense, and when it doesn't
Co-buying works when everyone involved has stable income, communicates honestly about money, and is willing to put the arrangement in writing. It doesn't work as a fix for someone who can't otherwise afford a mortgage alone, paired with someone unwilling to formalise anything. The one non-negotiable step is a Declaration of Trust. Get independent legal and mortgage advice before you sign anything.
Get started with Cohaus
Cohaus exists for exactly the situation this article describes: people who want to buy together but don't want to gamble on an informal handshake agreement. Where a private arrangement between friends leaves shares, exits and disputes to be worked out later, Cohaus builds community matching, shared deposit management and Declaration of Trust support into the process from day one.
That means less time spent guessing whether your co-buyer is financially compatible, and less risk of discovering gaps in your agreement only after something's gone wrong. If you're weighing up co-buying as your route into home ownership, visit the Cohaus platform to see how community matching and legal safeguards work together, and take the first step towards a properly structured co-buying plan.
Primary sources and further reading
For the legal foundations behind this guide, see GOV.UK's overview of joint property ownership and its separate page on the Shared Ownership scheme. Ashfords' practical guide for co-owners and Myerson's explainer on disputes between friends buying property cover what happens when things go wrong. For further reading, Cohaus's co-buying article library offers deeper coverage of each topic above.
This article is general information, not a substitute for advice from a qualified financial advisor. Consult a qualified financial professional about your own circumstances before acting on anything here.
Sources
- Gov
- Buying a house together? The legal low-down on co-ownership — Kiteleys Solicitors
- Joint ownership of property – a practical guide for co-owners | Ashfords
- Buying a property with friends: what happens if things go wrong — Myerson
- Half of buyers would co-purchase with friends or family to get on property ladder, data finds - The Intermediary