Unmarried Couples Buying Together: Joint Mortgage Risks & Protections

Unmarried couples buy homes together every day — and every day, some of them get into legal disputes that could have been prevented with simple paperwork. Without the legal framework that marriage provides, unmarried partners on a joint mortgage have to explicitly define ownership shares, decision-making rights, breakup protocols, and inheritance. This guide walks through tenancy in common vs joint tenancy, the cohabitation agreement that every unmarried couple should sign, the scenarios where one partner should be on the loan alone, and the specific risks of buying together without protection.

Tenancy in Common vs Joint Tenancy

How you take title to the property has major legal implications. The two main options for unmarried couples:

Joint tenancy with right of survivorship

Both partners own the property equally (50/50). If one partner dies, their share automatically passes to the surviving partner — no probate required. This is the default for many married couples and works for unmarried couples who want simple survivorship. Drawback: if you contributed unequal down payments or you want unequal ownership shares, joint tenancy doesn't reflect that.

Tenancy in common

Both partners own specified shares of the property (could be 50/50, 70/30, 80/20, or any other split). If one partner dies, their share passes through their will or state intestacy laws — not automatically to the surviving partner. This is generally better for unmarried couples because it accurately reflects unequal contributions and lets each partner control their own estate planning.

Most attorneys recommend tenancy in common for unmarried couples, with shares matching contribution to the down payment and ongoing mortgage payments. Combine TIC with a beneficiary designation or will that leaves your share to your partner, and you get the best of both worlds: accurate ownership reflection plus survivorship.

The Cohabitation Agreement: Essential Document

A cohabitation agreement is a written contract between unmarried partners that defines ownership, financial responsibilities, and breakup procedures. Without one, breakups can devolve into expensive legal battles over the home. With one, the path forward is clear and pre-agreed.

What the agreement should cover

Ownership shares (matching the deed): who owns what percentage. Down payment contributions: who paid how much, and whether the contribution affects ownership share. Monthly payment responsibilities: who pays the mortgage, taxes, insurance, utilities — and what happens if one partner stops contributing. Maintenance and improvement decisions: how decisions are made and how costs are split. Breakup procedures: if the relationship ends, what happens to the home (sell, one partner buys out the other, partition action). Dispute resolution: mediation, arbitration, or specific legal procedure.

Hire a real estate or family law attorney to draft the agreement. It typically costs $500-$2,000 and is worth multiples of that in protection. Both partners should have separate attorneys review the agreement before signing — this protects against later claims that the agreement was unfair or signed under duress.

Single vs Joint Mortgage Applications

Even if both partners are on the deed, only one needs to be on the mortgage. This is sometimes the right choice when one partner has significantly better credit or income than the other.

When one partner should apply alone

If one partner has 760+ credit and the other has 620 credit, the joint mortgage will be priced based on the lower score — costing $200-$400/month more on a typical loan. Applying alone with the higher-credit partner saves real money. Both partners can still be on the deed; only one is on the loan.

When joint application makes sense

When both incomes are needed to qualify for the home you want. When credit scores are similar. When you want both partners' credit history to reflect the mortgage (building credit history for both). When you want both partners to be legally responsible for the loan.

See our detailed [mismatched credit spouse guide](/blog/mortgage-mismatched-credit-spouse) for the financial trade-offs between joint and solo applications.

Unequal Down Payment Contributions

Unmarried couples frequently contribute unequal amounts to the down payment. The most common scenarios: one partner has more savings from before the relationship, one partner sold a previous home and contributed the equity, or one partner received an inheritance.

Best practice: document the contributions explicitly in your cohabitation agreement and structure ownership accordingly. If one partner contributes 80% of the down payment, tenancy in common with 70/30 or 80/20 ownership reflects that. The mortgage payments are typically split based on a different ratio (often 50/50 or proportional to income), but the ownership share reflects the initial investment.

When you sell or one partner buys out the other, the equity is divided based on ownership shares — not necessarily based on contribution to mortgage payments. This is why getting the structure right at purchase matters so much.

What Happens at Breakup

Unmarried couples don't get divorce courts to sort out their home. The options at breakup:

One partner buys out the other

The most amicable resolution. Both partners agree on a home value (typically via appraisal), calculate net equity, and the keeping partner pays the leaving partner their share — typically by refinancing the mortgage to pull out the equity needed for the buyout. Use our [cash-out refinance calculator](/tools/cash-out-refinance-calculator) to model the math.

Sell the home and split proceeds

The cleanest financial resolution. Both partners are released from the mortgage, and the net proceeds are split according to your ownership shares (or cohabitation agreement formula). Selling has transaction costs (typically 8-10% of sale price), so both partners lose some equity to closing costs and commissions.

Partition action (court-forced sale)

If you can't agree on what to do, one partner can file a partition action in court asking the judge to force the sale. This is the worst-case scenario — expensive (legal fees), public (court record), and time-consuming (6-18 months). Cohabitation agreements specify alternative dispute resolution to avoid partition.

Estate Planning for Unmarried Couples

Without marriage, your partner has no automatic right to inherit from you. If you die without a will, your share of the home passes through state intestacy laws — typically to your blood relatives, not to your unmarried partner. Even after living together for decades, the law doesn't recognize the relationship for inheritance purposes (with very narrow exceptions in a few states with common-law marriage).

Every unmarried couple buying a home together should also create: wills naming each other as beneficiaries of the home and other assets, durable powers of attorney for finances, healthcare powers of attorney for medical decisions, and HIPAA authorizations for medical information access. These documents collectively cost $1,000-$3,000 to draft properly and provide protection that married couples get automatically.

If you want absolute certainty about survivorship of the home: joint tenancy with right of survivorship (the property passes automatically) plus a will (just in case the joint tenancy is somehow challenged). The combination is bulletproof.

Tax Implications

Unmarried couples can't file taxes jointly. Each partner files separately. This affects mortgage tax deductions: each partner claims only their share of mortgage interest and property tax based on who actually paid it. Keep clear records of who paid what.

When you sell the home, each partner can claim the $250,000 capital gains exclusion (for property held 2+ years as primary residence). For a couple, this means up to $500,000 combined excluded — the same as married couples. The catch: you must each be on title and each meet the residency requirements.

Some couples use one partner's name on the deed and let the other contribute financially without legal ownership. This creates tax problems: only the named owner gets the mortgage interest deduction and capital gains exclusion. The non-owning partner has no equity protection. Almost never the right structure.

Frequently Asked Questions

Can I add my partner to the deed later if they're not on it now?

Yes. Adding a partner to the deed is done through a quitclaim or warranty deed signed by the current owner and recorded with the county. There may be tax implications (transferring 50% of a property worth $500,000 means giving your partner $250,000 of equity — potentially a taxable gift). Talk to a real estate attorney and tax professional before doing this.

What if my partner stops paying their share of the mortgage?

Both partners on the mortgage are jointly and severally liable — meaning the lender can pursue either one for the full payment, regardless of internal arrangements between partners. If your partner stops paying and you cover the full mortgage to protect your credit, you have a claim against your partner for their share — but enforcing that claim requires legal action.

Should we get married before buying a home together?

Marriage simplifies many of the legal questions (inheritance, tax filing, dispute resolution) but isn't strictly necessary. A well-structured tenancy in common with a cohabitation agreement provides most of the same protections. Don't get married just for the home purchase — that's a bigger decision. Do get married if you were going to anyway and the timing aligns.

Can common-law marriage help unmarried couples?

Common-law marriage exists in only a few states (Alabama, Colorado, DC, Iowa, Kansas, Montana, New Hampshire, Oklahoma, Rhode Island, South Carolina, Texas, and Utah, with varying requirements). Even where it exists, you must meet specific criteria — typically living together for a sustained period, holding yourselves out as married, and intending to be married. If you accidentally qualify as common-law married, you'll need a divorce to dissolve the relationship — including marital property division.

What if we want to break up but can't sell the home in a slow market?

Options: one partner moves out and continues paying their share of the mortgage from elsewhere (financially difficult), one partner buys out the other through a refinance (if equity supports it), rent out the home and split the rental income while waiting for the market (creates landlord obligations), or hold on jointly until conditions improve (requires civility and ongoing communication). Your cohabitation agreement should address this scenario explicitly.