Short answer: in most US states, the default rule is that the money in a joint account belongs to the two of you in proportion to what each of you put in, minus what each of you took out for yourself. The law calls that your “net contribution.” A minority of states follow a joint tenancy approach instead, and in New York that means a starting presumption of half each. In both systems, the account terms usually let the bank pay either one of you the whole balance on request.
Those two facts do not contradict each other. They answer different questions. The account agreement settles who may withdraw. State law settles who owns what was withdrawn. A joint account is very good at the first job and keeps only part of the evidence for the second one.
That gap is the subject of a May 2026 Iowa Law Review article by Reid Weisbord and Stewart Sterk. The net contribution rule, they write, “requires parties to preserve evidence of their net contribution, an unrealistic expectation when joint accounts remain in use for years or decades.” Their view is that many depositors “are probably unaware of the bookkeeping obligations” the rule puts on them.
This is not legal advice. Joint-account law is state law, and the statutes quoted here are examples, not a full map. Married couples who divorce are usually dealing with divorce and marital-property law as well, which this guide does not cover. If real money is in dispute, talk to a lawyer in your state.
Source: Joint Bank Accounts: Who Needs Them?, Weisbord & Sterk, Iowa Law Review 111:1647, 2026
Who owns the money in a joint bank account?
It depends on which of two models your state follows. Weisbord and Sterk describe them this way: courts apply either “the traditional joint tenancy approach, which presumes equal ownership of account funds by each party,” or “the Uniform Probate Code’s approach, which presumes ownership in proportion to each party’s net contribution.” They report that the net contribution rule is followed by most states, and that New York, the longest-standing joint tenancy state, has considered legislation to adopt it. The joint tenancy states do not all say the same thing, either: most of them, the authors write, “do not have a statutory rule or presumption for allocating lifetime ownership rights among joint accountholders.” New York is the clearest example of that approach, so it is the one used below.
The statutes read almost word for word alike. Maine’s version of the Uniform Probate Code says that during the lifetime of all parties, “an account belongs to the parties in proportion to the net contribution of each to the sums on deposit, unless there is clear and convincing evidence of a different intent.” California’s Probate Code section 5301 and Texas Estates Code section 113.102 say the same thing in nearly the same words.
New York goes the other way. Under Banking Law section 675, a deposit into an account payable to either holder or the survivor becomes “the property of such persons as joint tenants.” New York courts read that as a presumption that the depositor gave the other holder “a gift of a one-half interest in the deposited funds,” as the Appellate Division put it in Rosenzweig v Friedland (2011), quoting earlier cases.
Sources: Maine 18-C §6-211; California Probate Code §5301; Texas Estates Code §113.102; N.Y. Banking Law §675; Rosenzweig v Friedland, App. Div. 2d Dept, 2011
Why can either of you take all of it?
Because these statutes protect the bank when it pays, and leave the owners’ rights against each other for later. Texas puts it in one line: “A multiple-party account may be paid, on request, to any one or more of the parties.” Maine’s discharge section says a payment made under the account’s terms “discharges the financial institution from all claims for amounts so paid, whether or not the payment is consistent with the beneficial ownership of the account as between parties.”
California says the quiet part directly. Its discharge rule “has no bearing on the rights of parties in disputes between themselves” about who owns the money in the account or the money taken out of it. The bank is out of the fight. The fight still exists.
That is why a bank’s own explainer can be accurate and misleading at once. A credit union’s December 2025 guide to joint checking warns that “either party can withdraw all money in the account without the other’s consent.” The same page says “typically both parties have equal legal rights to the money in the account regardless of who made the deposits.” In a net contribution state, the right to withdraw and the right to keep are two separate things, and the deposits, along with own-use withdrawals and any proof of a different intent, decide the second one.
Sources: Texas Estates Code §113.202; Maine 18-C §6-226; California Probate Code §5405; Joint Checking Accounts: What to Know in 2026, Sunward Federal Credit Union, 2025-12-19; Schacht v. Kunimune, Alaska Supreme Court, 2019
What counts as your “net contribution”?
The statutes define it as a running balance per person. Texas’s wording: “the sum of all deposits made to that account by or for the party, less all withdrawals made by or for the party that have not been paid to or applied to the use of any other party, plus a pro rata share of any interest or dividends.” Maine and California use close variants.
Look at what that formula needs. For every deposit: whose money it was. For every withdrawal: whose use it went to. A bank statement shows amounts, dates and payees. It often does not show whose paycheck funded a deposit, and it does not say whether a grocery run was for one of you or both of you.
The bank is not going to fill that in. Texas says outright that a financial institution “may not be required to inquire, for purposes of establishing net contributions, about” the source of deposits or “the proposed application of an amount withdrawn.” Statements and transfer records still help, since a transfer from a named account shows where it came from. But the bank is not required to work out which deposits were one person’s money or which withdrawals were one person’s spending. That part is yours to keep.
The shared spending is the hardest part to read. The formula subtracts withdrawals for one party that were not applied to the use of the other, and a rent payment that housed both of you does not sit neatly on either side of that line. How a court treats years of shared rent, groceries and utilities between two holders is not something these statutes spell out. And Weisbord and Sterk report that, except between spouses, the Uniform Probate Code’s drafters “deliberately declined to provide a legal standard for resolving factual disputes concerning net contribution.”
Sources: Texas Estates Code §113.003; Maine 18-C §6-211; California Probate Code §5134; Weisbord & Sterk, 2026
A worked example: same account, three answers
These numbers are illustrative, chosen to keep the arithmetic simple. Two unmarried partners open a joint account. Over a year, Sam deposits $9,000 from their paycheck and Jordan deposits $3,000. Nothing leaves the account. At the breakup, the balance is $12,000.
The $3,000 gap between Sam’s first two answers is the whole story. Under a net contribution rule, Sam’s claim to it is only as good as Sam’s proof of where the deposits came from. In California, if Sam cannot prove the deposits at all, the statute’s equal-contribution presumption points to the half-each answer. Under the half-each presumption, Sam would have to rebut a presumed gift to get it back. And under the bank’s rules, either of them can ask the bank for all $12,000.
Real accounts are messier than this example. When an account also pays for shared costs, those costs are the part the statutes leave to courts. The example has no shared spending on purpose, so the three rules stay visible.
What happens if nobody kept records?
It depends on whether you were married and on which state you are in. Maine’s statute adds one sentence for spouses: “As between parties married to each other, in the absence of proof otherwise the net contribution of each is presumed to be an equal amount.” For everyone else, the Uniform Probate Code is silent. Weisbord and Sterk call this out: the drafters “intentionally declined to include a statutory presumption of ownership allocation for disputes in which unmarried accountholders lack proof of actual net contribution.”
In their words, that leaves unmarried holders choosing “between commissioning the costly forensic accounting necessary to establish proof of net contribution and rolling the dice on a judicially determined default allocation.” They also suspect the cost of “attributing every joint account transaction to an individual accountholder” keeps many of these disputes out of court entirely.
California fills the gap differently. Its definition section says that “in the absence of proof otherwise,” the net contribution of each party with a present right of withdrawal “is deemed to be an equal amount.” That presumption is not limited to spouses. In California, then, a partner who put in most of the money and kept no record may be starting from half.
Sources: Maine 18-C §6-211(2); California Probate Code §5134(b); Weisbord & Sterk, 2026
What if your ex already emptied the account?
The bank is usually not the place to recover it. The bank was allowed to pay. The claim, if there is one, is against the person who took more than their share.
California spells that claim out. If a party makes an excess withdrawal, the other parties “shall have an ownership interest in the excess withdrawal in proportion to the net contributions of each,” unless there is clear and convincing evidence of a contrary agreement. Only a living party, or someone acting for them, can bring the claim, and a court may reduce the recovery “to reflect funds withdrawn and applied for the benefit of the claiming party.” Money the account spent on you can count against what you get back.
New York measures the same claim against half. Each joint tenant “has the right as a joint owner of the bank account to withdraw a moiety (half) or less than a moiety for his own use,” the Appellate Division wrote in Rosenzweig, quoting the Court of Appeals.
The Uniform Probate Code itself does not address it. Its official comment, quoted by Weisbord and Sterk, says the net contribution section “does not undertake to describe the situation between parties if one party withdraws more than that party is then entitled to,” and leaves those rights to “general law other than this part.” Weisbord and Sterk call the comment’s statements “in some tension with one another.” So in a state that copied the uniform act word for word, how a court handles an over-withdrawal by a co-owner may turn on other law and on that state’s cases, not on the net contribution formula alone.
Two practical notes. First, some states let a holder stop the bank’s free-payment protection in advance. In Maine, the bank’s discharge does not cover payments made after it receives a party’s written notice that payments should not be permitted and has had a reasonable chance to act. California’s version is narrower: its written-notice rule excludes checking accounts, and its general discharge ends at a court order restraining payment.
Second, the bank’s account agreement may not settle the question. In McDaniels v. Rutter (Pa. Super. Ct. 2021), as Weisbord and Sterk describe it, an unmarried couple had broken up. Nine years after the breakup, one of them deposited $700,000 from a family inheritance into the joint account they still shared, and the ex-partner claimed $350,000 of it as a gift of half. The account agreement said the funds were owned “jointly, with right of survivorship,” and that boilerplate “proved unhelpful.” The court applied Pennsylvania’s net contribution statute instead, and the ex-partner failed to prove a gift by clear and convincing evidence.
The Alaska Supreme Court also looked past bank wording in Schacht v. Kunimune. There, a credit union agreement said the holders owned the accounts “jointly and equally … regardless of their net contributions,” and the court still applied the net contribution statute. But that was a dispute with a creditor, and the court read Alaska’s statute as not deciding disputes between the account owners themselves.
Sources: California Probate Code §5301(b)–(c); California Probate Code §5405; Rosenzweig v Friedland, 2011; Maine 18-C §6-226(2); Weisbord & Sterk, 2026, describing McDaniels v. Rutter, 262 A.3d 600 (Pa. Super. Ct. 2021); Schacht v. Kunimune, 2019
Why marriage changes the picture
Married couples have a second system behind the account. Weisbord and Sterk note that if one spouse breaches the marital trust, “divorce proceedings, with their attendant division of the parties’ assets, provide a backstop for the injured spouse—a backstop not generally available to unmarried cohabiting couples.” In most states, they add, unmarried partners “lack the legal protections regarding property division enjoyed by married spouses in a divorce proceeding.”
So the account-ownership statute carries the most weight for people without that second system: unmarried partners, housemates, friends who pooled money for a trip, siblings who share a bill account. For them, the joint-account statute may be the main rule for the money, and the record it asks for is one nobody was keeping.
The authors go further than most readers will. They argue that outside marriage, joint accounts are mostly unnecessary, and that for housemates sharing rent and utilities, “modern payment systems like Venmo and Zelle allow parties to instantaneously transfer funds to a single payee.”
How to share an account without losing track of whose money it is
Decide what the account is for, in writing
One line both of you sign or text: whether deposits are gifts to the pot or stay each person's money. Clear and convincing evidence of a different intent is what overturns the default in a net contribution state. In McDaniels v. Rutter, the ex-partner who claimed a gift could not meet that standard, and the bank's boilerplate did not help.
Deposit from traceable sources
Fund it by transfers from each person's own account rather than cash. A transfer from a named account is easier to trace later than a cash deposit.
Keep personal spending out of it
Every own-use withdrawal reduces your net contribution, and it is the one entry the statement cannot label for you. If it is only for you, pay from your own account.
Keep your own log of contributions
The bank is not required to ask whose money came in. A shared note or spreadsheet with who deposited what, and what each withdrawal paid for, is the record the statute assumes exists.
When it ends, divide it before anyone withdraws
Agree the split, then move the money. In some states a party's written notice to the bank limits what the bank can safely pay out; ask the bank what notice it accepts.
There is also the option the law review points to: don’t pool at all. Keep separate accounts and settle shared costs as they happen. Each payment between you is then its own transaction, with a date, an amount and a payer, instead of one more line in a pooled balance that someone would later have to attribute. For a running household balance over months, a ledger app like Splitwise is built for that job. For a single shared bill, such as a dinner, a grocery run or a bar tab, that is where splitty fits: scan the receipt, split it by item, and send each person a pre-filled payment request in their own payment app.
For the household side of this, see how couples choose between proportional, equal and pooled systems, why a shared bill divides the money but not the liability, and how long to keep a split record once a bill is paid. If the account is already part of a breakup, start with splitting costs with an ex. In the UK there is a second thing to undo: a joint account also links your credit files as a financial association, and closing the account does not remove that link by itself.
Common questions
FAQ
Questions & Answers
01 Can my partner legally take all the money out of our joint account?
The bank can usually pay them. Texas says a multiple-party account 'may be paid, on request, to any one or more of the parties', and Maine and California discharge the bank for payments made under the account terms even when they do not match who owns the money. Whether your partner may keep it is a separate question. In net contribution states, ownership follows each person's deposits less their own-use withdrawals; in New York, each holder is presumed to own half. A claim for an excess withdrawal runs against the person who took it, not the bank.
02 Who gets the money in a joint account when an unmarried couple breaks up?
In most states, it belongs to each of you in proportion to your net contribution, unless there is clear and convincing evidence that you intended something else. The Uniform Probate Code gives married holders a presumption of equal contributions but, as Weisbord and Sterk note, deliberately gives unmarried holders no default when the records are missing. California is an exception: absent proof otherwise, each party with a present right of withdrawal is deemed to have contributed equally. New York presumes half each.
03 Is money in a joint account split 50/50?
Only in some states and some situations. New York presumes joint tenancy, which courts read as a half interest for each holder. In Uniform Probate Code states such as Maine, married holders are presumed to have contributed equally unless proven otherwise. California deems equal contributions when there is no proof otherwise. But in a net contribution state, someone who can prove they deposited most of the money can claim most of the money.
04 What counts as a contribution to a joint account?
The statutes count deposits made by you or for you, minus withdrawals made by you or for you that were not paid to or used for the other holder, plus a proportional share of interest. Texas, Maine and California all use versions of that formula. A bank statement shows amounts and payees, but Texas says the bank is not required to ask where deposits came from or what withdrawals were for, so the record of whose money it was is mostly yours to keep.
05 Does the bank's account agreement decide who owns the money?
Not necessarily. In McDaniels v. Rutter, a Pennsylvania case between two former partners, the account agreement said the money was owned jointly with right of survivorship, and Weisbord and Sterk report that this boilerplate proved unhelpful. The court applied the state's net contribution statute, and the ex-partner who claimed half of a $700,000 deposit could not prove a gift by clear and convincing evidence. In Schacht v. Kunimune, the Alaska Supreme Court applied its net contribution statute even though a credit union agreement said the holders owned the accounts jointly and equally regardless of contributions. That case was a creditor dispute, though, and the court said Alaska's statute does not decide disputes between the owners themselves.
06 Should couples who aren't married have a joint account?
That is a judgment call, but go in knowing the trade. The account makes shared payments easy and gives either of you the power to withdraw everything. In most states it leaves ownership to depend on a contribution record you have to keep yourselves. Weisbord and Sterk argue that outside marriage joint accounts are largely unnecessary, and that housemates can pay one payee directly with apps like Venmo and Zelle. If you do share one, fund it by transfer, keep personal spending out of it, and write down what each deposit is meant to be.