How joint mortgages work
A joint mortgage allows two (or sometimes more) people to borrow together to purchase a property. Both applicants' incomes are considered in the affordability assessment, typically allowing you to borrow significantly more than you could alone. Most lenders accept joint applications from couples (married, civil partnership, or cohabiting), friends, or family members.
The key point to understand is that on a joint mortgage, both parties are jointly and severally liable for the full debt. This means if one person stops paying, the other is responsible for the entire mortgage — not just their half. The lender can pursue either borrower for the full outstanding amount.
Joint tenants vs tenants in common
When buying jointly, you must choose how you hold the property. This is one of the most important decisions you will make, and it is often not explained properly to first time buyers.
Joint tenants
Under joint tenancy, both owners have equal rights to the entire property. If one owner dies, the property automatically passes to the surviving owner regardless of what any will says. This is called the right of survivorship. Joint tenancy is most common for married couples and civil partners.
Tenants in common
Under tenancy in common, each owner holds a defined share of the property — which does not have to be equal. You might own 60% and your co-buyer 40%, reflecting different deposit contributions. Each owner can leave their share to whoever they choose in their will. If one owner dies without a will, their share passes under intestacy rules, not automatically to the co-owner.
If you are buying with a friend, sibling, or unmarried partner, tenants in common is almost always the better choice. It protects each person's financial contribution and gives clarity about ownership shares.
The declaration of trust
When buying as tenants in common, you should have a solicitor draw up a declaration of trust (also called a deed of trust). This legally binding document records:
- Each person's share of the property
- How much each person contributed to the deposit
- How mortgage payments and household costs will be split
- What happens if one person wants to sell and the other does not
- How proceeds will be divided on sale
- What happens if the relationship breaks down
A declaration of trust typically costs £200–£500 and is well worth the expense. Without one, disputes about ownership shares can end up in court — which is vastly more expensive and stressful.
Buying with a partner — married vs unmarried
Married couples and civil partners have legal protections under family law. If the relationship breaks down, the courts can redistribute property regardless of who owns what proportion, based on factors like children, income, and needs.
Unmarried cohabiting couples have no such automatic protections under English and Welsh law. If you are not married and do not have a declaration of trust, disputes about the property can be extremely difficult and expensive to resolve. The law does not recognise common-law marriage in England and Wales, regardless of how long you have lived together.
Buying with a friend or family member
Buying with a friend is becoming more common as property prices make solo purchases unaffordable. The same principles apply — use tenants in common, get a declaration of trust, and agree upfront what happens if one person wants to sell. Additional considerations include:
- Exit strategy: Agree a process for one person buying the other out or selling the property
- Notice period: How much notice must one person give before triggering a sale?
- Valuation method: Agree how the property will be valued if one person wants to sell their share
- Living arrangements: What if one person wants to move out but keep their ownership share?
Stamp duty implications
When buying jointly, first time buyer stamp duty relief applies only if both applicants qualify as first time buyers. If one person has previously owned a property, neither of you gets the relief, and you pay the standard residential rates. This can add thousands of pounds to the purchase cost.
Worse, if one applicant already owns another property (even an inherited one), the additional property stamp duty surcharge of 5% may apply to the entire purchase price. This is a significant cost that catches many joint buyers off guard.
What if one person has bad credit?
Both applicants' credit histories are assessed on a joint mortgage. If one person has adverse credit (missed payments, CCJs, defaults), it can affect the application for both of you. Options include:
- Applying to specialist lenders: Some lenders are more flexible about one applicant having credit issues
- Sole application: The person with good credit applies alone, using only their income. This reduces borrowing power but avoids the credit issue.
- Joint borrower sole proprietor: Some lenders offer products where both incomes are used for affordability but only one person is on the property title
A first time buyer mortgage broker can advise on the best structure for your specific situation and identify lenders most likely to approve your application.
What happens if the relationship breaks down?
This is the scenario nobody wants to plan for but everyone should. Without proper agreements in place:
- If you are joint tenants, both of you own the whole property — neither can sell their share independently without severing the tenancy first
- If you are tenants in common without a declaration of trust, disputes about who paid what and who gets what can be costly to resolve
- The mortgage must continue to be paid regardless of relationship status. If one person stops paying, the other is liable.
- One person can apply to the court for an order of sale, but this is expensive and time-consuming
Get legal advice and a declaration of trust before you buy. It is far cheaper than sorting things out after a breakdown.
If you are considering buying jointly, speak to a first time buyer mortgage broker who can structure the application for the best possible outcome. Get Matched Free with a specialist today.