A joint tenant brokerage account is an investment account owned by two or more people together, where each owner has equal authority to trade, withdraw, and manage the assets, and where, under the most common version, the deceased owner’s share passes directly to the surviving owner without going through probate. The structure you pick when you open the account controls almost everything that follows: how assets transfer at death, how creditors can reach them, how income gets taxed, and how much flexibility you have if the relationship between owners changes.
How the Account Works Day to Day
Any two or more competent adults can open one together. Marriage isn’t required. Spouses, siblings, business partners, and friends all qualify. Every owner signs the account agreement, and once the account is open, every owner has full trading authority.
That full authority cuts both ways. Any single owner can sell positions, move cash, or liquidate the whole portfolio without checking with anyone else first. The brokerage will not call your co-owner before processing the order. The flip side is shared liability: if one owner runs up margin debt or leaves the account negative, every owner is jointly and severally liable, and the firm can collect from whichever owner is easiest to reach.
The Ownership Structures You Can Choose
Three structures are available, and the differences between them matter more than most of the day-to-day mechanics.
Joint Tenants With Right of Survivorship (JTWROS)
JTWROS is the default most married couples pick and the most common structure overall. When one owner dies, their share transfers immediately to the surviving owner by operation of law. The assets never enter the deceased owner’s probate estate. The survivor provides a certified death certificate to the brokerage, and the firm retitles the account into their name alone, usually within a few weeks.
Every JTWROS owner holds an equal, undivided interest. You cannot own 70% while your co-owner holds 30%. If three people hold a JTWROS account and one dies, the remaining two each own half.
Tenants in Common (TIC)
TIC is the right choice when you want your share to pass to your own heirs rather than to your co-owner. There is no right of survivorship. When a TIC owner dies, their percentage goes to their estate and is distributed under their will or state intestacy law.
TIC allows unequal ownership, set when the account is opened. The tradeoff is speed. The deceased owner’s share is frozen until the brokerage receives court-issued letters testamentary or letters of administration. The surviving co-owner keeps full access to their own portion but cannot touch the rest during probate.
Tenancy by the Entirety (TBE)
TBE is available only to married couples, and only in roughly 25 states plus Washington, D.C. Not every state that recognizes TBE applies it to brokerage accounts; about 15 extend it to all property types, while others limit it to real estate. Where it is available for investment accounts, it offers something JTWROS does not: protection from the creditors of one spouse acting alone.
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. The protection falls away if the debt is joint, if the couple divorces (which converts TBE to tenancy in common), or if a federal tax lien is involved. TBE also carries the right of survivorship, so at death it operates like JTWROS.
What Happens When One Owner Dies
Two things depend on the structure you chose: how fast the survivor gets control, and how much of a tax break comes with the assets.
For JTWROS, transfer is automatic on presentation of a death certificate. For TIC, the deceased’s share is frozen until probate produces letters authorizing someone to act for the estate. Timing 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 on the date of death. For an appreciated portfolio, that reset can erase a large capital gains bill for the heir. How much of a joint account gets the step-up depends on both the ownership type and the relationship between the owners.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 who 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 tighter. 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 steps up equals the percentage the decedent actually funded. If you and your sibling each put in half, half steps up. If your parent funded the whole thing, the whole thing 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 accounts, the deceased’s share always receives a full step-up, and the surviving owner’s share keeps its original basis.
Community Property States
Married couples in Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, and Wisconsin may do better than JTWROS allows. When one spouse dies, the entire community property interest, including the survivor’s half, receives a step-up in basis.3Office of the Law Revision Counsel. 26 USC 1014 – Basis of Property Acquired From a Decedent That resets 100% of the account, compared to 50% under spousal JTWROS in a non-community-property state. For a highly appreciated portfolio, the difference can run into tens of thousands in avoided capital gains tax. Talk to a tax advisor before defaulting to JTWROS if you live in one of these states.
How Taxes Are Reported Each Year
The brokerage issues a single set of tax forms, including the 1099-DIV, 1099-INT, and 1099-B, under the Social Security number of the primary account holder. The IRS initially sees all of the income as that one person’s, even though every owner is legally responsible for their own share.
If you are the primary holder and part of the income actually belongs to your co-owner, you reallocate it through a nominee return. You file a new 1099 of the same type with the IRS, listing yourself as the payer and your co-owner as the recipient, along with a Form 1096 transmittal. You give your co-owner a copy for their own return, and each of you reports only your portion. Spouses holding an account jointly can skip the nominee paperwork and simply divide the income between their returns.4Internal Revenue Service. General Instructions for Certain Information Returns (2025)
Gift Tax on Unequal Contributions
If one owner puts in substantially more than the other, gift tax can enter the picture. For securities titled jointly with right of survivorship, the IRS treats the funding as an immediate gift of half the value to the co-owner. (Joint bank accounts are different; no gift occurs there until the non-contributing owner withdraws for their own benefit.)5Internal Revenue Service. Instructions for Form 709 (2025)
If the gift to any single person exceeds the annual exclusion ($19,000 in 2026), the contributing owner must file IRS Form 709.6Internal Revenue Service. Frequently Asked Questions on Gift Taxes Filing doesn’t necessarily mean you owe tax; the excess counts against your lifetime exemption. Not filing is the mistake that catches people off guard.
Creditor and Dispute Risks
Unless the account is held as tenancy by the entirety in a state that recognizes it for brokerage assets, a joint account is exposed to the debts of any single owner. If one co-owner is sued, files bankruptcy, or has a judgment entered against them, creditors may be able to reach the joint assets. The other owner may have to spend money defending their interest even if they contributed every dollar in the account. That exposure is what makes JTWROS between non-spouses risky when one owner has business liabilities or shaky personal finances.
Disagreements between owners are harder to resolve than people expect. You can ask the brokerage to freeze the account until you work out a split, and to actually divide the assets you generally submit a written request to close the joint account and open new individual accounts with a specific allocation of each position.7FINRA. 6 Tips for Managing Investments Through Divorce Some proprietary investment products may not transfer to another firm, and liquidating them can trigger fees, penalties, or taxable gains.
SIPC Coverage
If the brokerage firm fails, the Securities Investor Protection Corporation covers up to $500,000 per account, including up to $250,000 in cash. A joint account qualifies for its own $500,000 of SIPC protection separate from any individual accounts the owners hold at the same firm.8SIPC. Investors with Multiple Accounts
Opening the Account and Changing It Later
Opening a joint brokerage account takes government-issued ID from every owner and a signed account agreement that names the ownership type. Some firms want all owners present or notarized signatures; most major online brokerages now handle the whole process digitally, verifying each owner separately.
Changing the structure later is harder than people expect. Converting JTWROS to TIC, or the reverse, usually means closing the 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 the existing holdings. Removing a co-owner raises the same issues. Neither move is casual, and both are worth running past a tax advisor before you call the brokerage.