A joint tenant brokerage account is an investment account owned by two or more people together, where every owner has equal authority to trade, withdraw, and manage the assets, and — in its most common form — the surviving owner automatically inherits the deceased owner’s share without probate. Any two competent adults can open one. You don’t need to be married or related. Spouses, siblings, business partners, and friends all qualify.
How Shared Ownership Actually Works
Once the account is open, every owner signs the account agreement and every owner gets full trading authority. That authority is both the appeal and the danger. Any single owner can execute trades, move cash, or liquidate the whole portfolio without asking anyone else first. The brokerage will not call your co-owner to confirm your sell order.
Liability runs the same way. If one owner runs up margin debt or leaves the account with a negative balance, all owners are jointly and severally liable. The brokerage can collect from whichever owner is easiest to reach, no matter who placed the trade.
The Ownership Type Is the Real Decision
When you open the account, you choose an ownership designation. That choice controls what happens at death, how creditors can reach the assets, and how ownership percentages are treated. There are three common structures.
Joint Tenants With Right of Survivorship
JTWROS is the default for most married couples and the most popular structure overall. Its defining feature is the right of survivorship: when one owner dies, their share transfers immediately to the surviving owner by operation of law. The assets never enter the deceased’s probate estate. The survivor sends a certified death certificate to the brokerage, and the firm retitles the account.
Every JTWROS owner holds an equal, undivided interest. You cannot own 70% of a JTWROS account while your co-owner holds 30%. If three people hold an account this way and one dies, the remaining two each own half.
Tenants in Common
Tenants in common is the right structure when you want your share to go to your own heirs rather than to your co-owner. There is no right of survivorship. A deceased owner’s percentage passes to their estate and is distributed according to their will or state intestacy law.
TIC also allows unequal ownership. One owner can hold 60% and the other 40%, with those percentages set when the account is established. The tradeoff is speed. Because the deceased’s share must go through probate, the brokerage freezes that portion until it receives court documentation, such as letters testamentary or letters of administration. The surviving co-owner keeps full access to their own share but cannot touch the deceased’s portion during that process.
Tenancy by the Entirety
Tenancy by the entirety is available only to married couples, and only in roughly 25 states plus Washington, D.C. Not all of those states extend TBE to brokerage accounts; about 15 allow it for all property types, while others limit it to real estate. Where it is recognized for investment accounts, it offers something JTWROS cannot: protection from creditors of one spouse.
Under TBE, the marriage itself is treated as the owner. Neither spouse holds a divisible share, so a creditor with a judgment against only one spouse generally cannot force the sale of TBE property. That shield disappears if the debt is joint, if the couple divorces (which converts TBE to tenants in common), or if a federal tax lien is involved. TBE includes the right of survivorship, so at death it works like JTWROS.
What Happens When an Owner Dies
With JTWROS or TBE, the surviving owner submits a certified death certificate to the brokerage and the firm removes the deceased owner’s name. No court order, no executor. This is usually complete within a few weeks.
With TIC, the brokerage freezes the deceased owner’s percentage share. The estate’s executor or administrator must present court-issued letters testamentary or letters of administration before the brokerage will release that portion. How long that takes depends on the probate court and whether the will is contested.
The Step-Up in Basis
When someone dies, the tax cost basis of their assets generally resets to the fair market value at the date of death. That step-up can save the heir significant capital gains taxes on appreciated investments. How much of a joint account gets it depends on the ownership structure and who the owners are.1Office of the Law Revision Counsel. 26 US Code 1014 – Basis of Property Acquired From a Decedent
For spousal JTWROS accounts, exactly half the account value gets a step-up, regardless of which spouse contributed what. The IRS treats spousal joint tenancies as qualified joint interests and automatically includes half in the deceased spouse’s gross estate.2Office of the Law Revision Counsel. 26 US Code 2040 – Joint Interests
For non-spousal JTWROS accounts, the rule is less generous. The IRS presumes the entire account belongs to the decedent’s estate unless the surviving owner can prove they contributed their own money. The portion that gets a step-up equals whatever percentage the decedent actually funded. If you and your sibling each put in half, half the account gets a step-up. If your parent funded the whole thing, the entire account steps up at their death. Keep contribution records; the burden of proof falls on the survivor.2Office of the Law Revision Counsel. 26 US Code 2040 – Joint Interests
For TIC, the deceased’s share always receives a full step-up, and the surviving owner’s share keeps its original basis. Married couples in community property states (Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, and Wisconsin) may get a better deal still: at the first spouse’s death, the entire community property interest, including the survivor’s half, receives a step-up. Talk to a tax advisor before defaulting to JTWROS in those states.3Office of the Law Revision Counsel. 26 USC 1014 – Basis of Property Acquired From a Decedent
Taxes While Both Owners Are Alive
The brokerage issues a single set of tax forms (1099-DIV, 1099-INT, 1099-B) under the Social Security number of the primary account holder. The IRS initially sees all the income as belonging to one person, even though each owner is legally responsible for their share.
If you are the primary holder and the 1099 shows income that partly belongs to your co-owner, you reallocate it through a nominee return: file a new Form 1099 of the same type listing yourself as the payer and your co-owner as the recipient, with a Form 1096 transmittal, and give your co-owner a copy for their return. Spouses filing jointly can skip this and just divide the income between their returns.4Internal Revenue Service. General Instructions for Certain Information Returns (2025)
Gift Tax on Unequal Contributions
Funding matters. When you use your own money to purchase securities titled in joint names with right of survivorship, the IRS considers that an immediate gift of half the value to your co-owner. (Joint bank accounts work differently: no gift occurs until the non-contributing owner actually withdraws funds.)5Internal Revenue Service. Instructions for Form 709 (2025)
If the gift to any single person exceeds the annual gift tax exclusion ($19,000 in 2026), the contributing owner must file Form 709.6Internal Revenue Service. Frequently Asked Questions on Gift Taxes Filing the form does not necessarily mean you owe tax, since the excess counts against your lifetime exemption. Not filing it is the mistake that catches people off guard.
Risks Worth Understanding Before You Sign
Unless you hold the account as tenancy by the entirety in a state that recognizes it for investment accounts, a joint brokerage account is exposed to the debts of any single owner. If one co-owner gets sued, files bankruptcy, or has a judgment entered against them, creditors may be able to reach assets in the joint account. The other owner may spend money defending their interest even if they contributed every dollar. This is what makes non-spousal JTWROS accounts risky when one owner has business liabilities or shaky finances.
Co-owner disagreements are the other soft spot. If you and a co-owner clash over strategy or one of you makes trades the other objects to, options are limited. You can ask the brokerage to freeze the account while you negotiate. Actually splitting it usually means submitting a written request to close the joint account and open new individual accounts, specifying how each position gets allocated.7FINRA. 6 Tips for Managing Investments Through Divorce Some proprietary products may not transfer to a different firm, and liquidating them can trigger fees, penalties, or taxes.
Opening and Changing the Account Later
Opening a joint brokerage account requires government-issued ID from every owner and a signed account agreement specifying the ownership type. Some firms require all owners to appear in person or provide notarized signatures; most major online brokerages allow the process to be completed digitally, with each owner verifying identity separately.
Changing the ownership structure afterward is harder than most people expect. Converting JTWROS to TIC, or the reverse, often requires closing the old account and opening a new one. Adding a co-owner is treated as a transfer of ownership, which can trigger gift tax reporting and affect the cost basis of existing holdings. Removing a co-owner raises the same issues. Neither move should be made casually, and both are worth running past a tax advisor before you call the brokerage.