If you own a third of a house, you have the right to use the entire property, the obligation to pay your share of the costs, the freedom to sell or will away your interest, and the power to ask a court to force a sale if co-ownership stops working. What you cannot do is sell the whole house, mortgage it, or make major changes to it without the other owners’ consent. The exact contours of these rights depend on how the deed is written, whether you signed a co-ownership agreement, and the property law of your state.
Check the Deed First
Before anything else, look at how the deed describes the ownership. That single detail controls almost everything that follows.
A one-third interest almost always means you hold the property as a tenant in common. Tenancy in common lets each owner hold a different percentage, sell or transfer independently, and pass the share through a will. There is no automatic transfer to the other owners at death.1Legal Information Institute. Tenancy in Common
Joint tenancy requires equal shares among all owners and carries a right of survivorship, so a three-way joint tenancy with equal thirds is possible but less common for unrelated buyers. Tenancy by the entirety is limited to married couples in states that recognize it and does not fit a three-way split at all.2Legal Information Institute. Tenancy by the Entirety The rest of this article assumes tenancy in common, which is where most one-third situations land.
You Have the Right to Use the Whole House
A one-third share does not entitle you to one-third of the rooms. Every tenant in common has the right to occupy and use the entire property, no matter the size of their interest.1Legal Information Institute. Tenancy in Common You can live there, keep belongings there, and come and go. Your co-owners have the same right. No one gets to carve off an exclusive bedroom or floor unless everyone agrees to that in writing.
If a co-owner locks you out or threatens you to keep you away, that is called ouster. You can go to court to restore your access, and the co-owner who kept you out owes you fair rental value for the time you were excluded. The threshold is real exclusion, not interpersonal tension. If you simply find living there uncomfortable and move out voluntarily, most courts hold that the remaining occupant owes you nothing for using the property alone. The difference between being pushed out and walking out matters a great deal.
Who Pays for What
Each co-owner is expected to contribute to property taxes, insurance, and necessary repairs in proportion to their share. With a one-third interest, your share of those recurring costs is a third. If you end up covering more than that, you can bring a contribution action against the others to recover the overpayment.
The mortgage works differently. If all three of you signed the loan, the lender treats each borrower as jointly and severally liable for the full balance. Your ownership percentage is irrelevant to the bank. If the other two stop paying, you are on the hook for the entire monthly payment, not just your third, and the house is at risk of foreclosure if the shortfall is not covered.
There is a wrinkle on contribution claims when one co-owner is also living in the property alone. In many states, the non-occupying owners can offset what they owe for taxes and maintenance against the fair rental value of that exclusive use. The accounting runs both ways.
Improvements are not the same as maintenance. You generally cannot force the other owners to reimburse you for upgrades they did not agree to. If you remodel the kitchen on your own initiative, you absorb that cost up front. If the property is later partitioned or sold, you may be credited for any increase in value your improvements produced.
What You Can and Can’t Decide Alone
No single co-owner can sell the whole property, place a mortgage on the whole property, or make fundamental changes to it without the consent of every other owner. That unanimity rule protects you from being outvoted, but it also means any one of your co-owners can block something you want to do.
Day-to-day upkeep is different. Necessary repairs that keep the house habitable and sound can be handled by any co-owner, with the cost allocated proportionally afterward. The line between a necessary repair and an optional improvement is blurry in practice, which is where many disputes start.
Selling or Passing On Your Share
You can sell or transfer your one-third interest to anyone without asking the other owners for permission.1Legal Information Institute. Tenancy in Common You can also leave it to someone in your will or pledge it as collateral for a loan. That freedom is a defining feature of tenancy in common.
Selling a fractional share on the open market is harder than selling a whole house. Buyers understand they would be inheriting relationships with strangers and sharing control of major decisions, so most demand a steep discount. Expect to receive meaningfully less than a third of the home’s full market value if you try to sell your share this way.
A right of first refusal, giving the other owners the first chance to buy before you offer the share to outsiders, is not a default rule. It applies only if it was written into a co-ownership agreement. Without that clause, you can sell to whomever you choose.
If a Co-Owner Stops Paying the Mortgage
This is the risk that blindsides many fractional owners. Because co-borrowers are jointly and severally liable, the lender can hold any one of you responsible for the entire remaining balance. You can be paying your third on time every month and still face foreclosure because someone else did not pay theirs. Missed payments also hit the credit reports of every borrower on the loan, not just the one who defaulted.
If this happens, your options are to cover the full payment and pursue a contribution claim against the defaulter, try to refinance the mortgage into your own name, negotiate a sale among the owners, or file for partition. None of these are quick or cheap, which is why the financial reliability of the people on your deed matters as much as the deed itself.
What Happens If a Co-Owner Dies
Under tenancy in common, a deceased owner’s share does not pass to you. It becomes part of their estate and goes to whoever is named in their will, or to their heirs under state intestacy law if there is no will. You could end up owning the property with the deceased’s spouse, children, or other relatives you have never met. This is one of the more disruptive events in shared ownership, and it happens more often than people plan for.
Joint tenancy produces the opposite result. The deceased owner’s share passes automatically to the surviving joint tenants through the right of survivorship, skipping probate. If three equal joint tenants hold a house and one dies, each survivor ends up owning half. Tenancy by the entirety works the same way between spouses.2Legal Information Institute. Tenancy by the Entirety
If you want any say in who eventually ends up owning the other shares, a written co-ownership agreement with buyout provisions is the practical tool for that. Without one, the deed and state law decide.
Forcing a Sale Through Partition
When co-ownership becomes unworkable, any owner can file a partition action asking the court to end the arrangement. This right exists in every state and cannot be blocked by the other owners’ refusal to go along. It is the ultimate exit for a trapped co-owner.
Courts resolve partition in one of two ways. Partition in kind physically divides the property, giving each owner a separate parcel with independent title; this is realistic for raw land but almost never for a single-family home. Partition by sale orders the property sold and distributes the proceeds by ownership share, after debts, liens, and sale costs are paid off the top. For houses, partition by sale is far more common.
Partition is expensive. Legal fees frequently run into five figures, the process takes months, and court-ordered sales often produce lower prices than voluntary listings because the timing is compressed and buyers sense distress. If a buyout or voluntary sale can be negotiated instead, you will almost always come out ahead.
During partition, the court also performs an accounting. Overpayments on taxes or maintenance, credits for improvements that increased value, and rental-value credits for ouster or exclusive occupancy are sorted out at this stage and reflected in each owner’s cut of the proceeds.
Risk From Your Co-Owners’ Creditors
A judgment creditor can place a lien against a single co-owner’s share without touching the other owners’ interests, as long as the property is not held as tenancy by the entirety. Your one-third stays unencumbered if a creditor records a judgment against one of the other owners.
The practical difficulty is that a lien on one share makes the whole property harder to sell cleanly, because buyers want clear title. In some cases the creditor can force a sale of the debtor’s share or push for partition. You could end up co-owning with a creditor whose only goal is a fast sale. Paying attention to the financial health of the other people on your deed is a basic form of self-protection.
Tax Deductions You Can Claim
If you itemize, you can deduct the share of mortgage interest and property taxes you actually paid during the year. Paying a third of the interest and a third of the taxes means deducting a third of each on your own return. The mortgage servicer typically sends Form 1098 to only one borrower, so if that is not you, you report your share on Schedule A and identify the person who received the 1098.3Internal Revenue Service. Other Deduction Questions 2 Keep written records of how payments were split among the owners in case the IRS asks.
The federal cap on state and local tax deductions applies per return, not per property, so each co-owner who files separately gets their own cap.
Renting the House Out
You cannot unilaterally lease the property or any part of it to a tenant. Renting requires agreement among all co-owners on the lease terms, the tenant, the rent, and how the income is divided. Rental income is normally split according to ownership shares, so your cut would be one-third unless everyone agrees to a different arrangement, which should be put in writing.
Why a Written Agreement Matters
A co-ownership agreement is the most effective way to prevent the problems above. It is a private contract that fills in the gaps the deed leaves open. A workable agreement covers how expenses are split and paid, which decisions require unanimity and which do not, how a departing owner’s share is valued and bought out, whether the other owners get a right of first refusal, how disputes are handled before anyone files suit, and who lives at the property and on what terms.
To be enforceable, most courts require the agreement to be in writing and signed by all owners. Clauses that conflict with state property law may not hold up, so an attorney review is worth the cost. If you are entering a co-ownership and the others resist putting anything in writing, treat that as a warning. The owners most reluctant to document expectations tend to be the ones who create disputes later.