Joint Accounts: Investing Together with a Partner
A joint brokerage account is owned by two or more people. The most common type is Joint Tenants with Rights of Survivorship (JTWROS) — when one owner dies, the surviving owner inherits the account without probate. Over 50% of household brokerage accounts are joint accounts, primarily held by married couples.
Joint accounts are most commonly used by married couples to manage household finances together. Both account holders have equal access to the account — each can deposit, withdraw, trade, and manage investments independently. This "either-or" ownership means that either spouse can act on behalf of the account without the other's signature. Joint accounts simplify estate planning because the assets pass directly to the surviving spouse without going through probate. They also ensure that both partners have visibility into the household's financial situation and can manage it if one spouse becomes incapacitated.
There are three main types of joint ownership in the US. Joint Tenants with Rights of Survivorship (JTWROS) is the most common — when one owner dies, their share automatically transfers to the surviving owner(s). Tenants in Common (TIC) allows owners to specify their percentage interest (e.g., 60%/40%), and when one dies, their share goes to their estate, not automatically to the other owner. Community Property (available in AZ, CA, ID, LA, NV, NM, TX, WA, WI) treats assets acquired during marriage as equally owned by both spouses and provides a "step-up in basis" for the entire account when one spouse dies — this can be a significant tax advantage.
Real-world example: A married couple in California (a community property state) opens a joint brokerage account with $500,000. They hold $500,000 of appreciated stock with a basis of $200,000 (unrealized gain of $300,000). When one spouse dies, the entire account receives a "step-up in basis" to the current market value of $500,000. The surviving spouse can sell immediately with zero capital gains tax. In a non-community property state using JTWROS, only the deceased spouse's half would receive a step-up — the surviving spouse's half retains the original basis. The tax savings from community property step-up can be worth tens or hundreds of thousands of dollars.
Tax Implications of Joint Accounts
Joint accounts have complex tax rules. Dividends, interest, and capital gains are reported under the first owner's Social Security number listed on the account (the "primary" owner). The IRS generally expects a 50/50 split of income for married couples filing jointly (it does not matter — they file jointly anyway). For non-married partners, the income should be reported according to each person's ownership percentage. Gift tax rules: if one person contributes more than the other to a JTWROS account, the excess contribution may be treated as a gift. For 2026, the annual gift tax exclusion is $19,000 per person per donee. Contributions above this amount must be reported on Form 709.
FAQs
Should I use a joint account or separate accounts?
Married couples often benefit from both. A joint account for household expenses and shared investments simplifies management, ensures both partners can access funds, and provides survivorship benefits. Separate accounts allow each spouse to pursue independent investment strategies, gift assets separately, and maintain individual tax planning flexibility. Many couples use the "yours, mine, and ours" approach: a joint account for joint expenses and goals, plus individual accounts for personal investments. For estate planning purposes, having some assets in each spouse's name enables flexibility with the step-up in basis.
What happens to a joint account when one owner dies?
In JTWROS, the surviving owner automatically becomes the sole owner. The account should be retitled in the survivor's name by contacting the broker and providing a death certificate. The assets do not go through probate — they pass directly to the survivor. The cost basis of the deceased owner's share is "stepped up" to the date-of-death value (for non-community property states, only the deceased's half steps up; for community property, the entire account steps up). The survivor can continue managing the account or liquidate it. If the account is TIC, the deceased's share passes through their estate and may require probate.
Can I open a joint account with someone who is not my spouse?
Yes — you can open a joint account with a family member (parent, child, sibling), domestic partner, or business partner. However, non-spouse joint accounts have significant risks. Either owner can withdraw all the money without the other's consent. The account may be subject to claims against either owner (creditors, lawsuits, divorce). Gift tax may apply if one person contributes more than the other. Estate planning becomes complicated. Before opening a non-spouse joint account, consult an attorney. Consider alternatives: a trust account, power of attorney, or a separate custodial account may be more appropriate depending on the relationship and purpose.