Both account holders can sign checks, but the bank sets the rules

Yes, both of you can sign checks on a joint checking account — but whether you must both sign, or whether either one of you can sign alone, depends entirely on how you set up the account. When you opened the joint account, you and the other owner chose a signing structure. That choice stays in place unless you go back to the bank and change it.

The two main structures are "either/or" signing (either account holder can sign checks alone) and "both required" signing (both must sign every check). Most joint accounts default to either/or, which means one person can write and sign a check without the other's knowledge or permission. If you need both signatures on every check, you have to request that explicitly when you open the account, and the bank will flag it in their system.

Key Takeaways

  • Your account's signing rules were set when you opened it, and they determine whether one person or both people must sign each check.
  • Either/or signing (one person can sign alone) is the default for most joint accounts unless you specifically requested both-required signing.
  • You can change your signing structure by contacting your bank, but the change applies to all future checks, not past ones.
  • If you suspect someone signed a check without authority, report it to your bank as soon as you notice it — the bank's fraud process depends on timing.
  • A check signed by only one account holder on a both-required account may still clear, but the bank can reverse it if the other owner disputes it.

How to find out which signing structure you have

Call your bank's customer service line or log into your online account and look for the account details or account agreement section. The bank will list your account type and signing requirements. You can also ask to see a copy of the signature card you signed when you opened the account — that document shows which signing structure was chosen.

If you cannot find the information online or in your records, go to a branch in person with your ID and ask a banker to pull up your account setup. They can tell you in minutes whether the account requires one signature or two on every check.

What happens if one person signs when both are required

If your account requires both signatures and someone writes a check signed by only one person, the check may still clear — banks do not always catch this at the teller window, especially if the check is deposited at an ATM or mobile app rather than handed to a person. The problem surfaces later, when the other account holder sees the transaction and disputes it.

Once a dispute is filed, the bank can reverse the check and return the funds, even if it cleared days or weeks earlier. The person who received the check will see the deposit reversed, which can create a mess if they have already spent the money. This is why both-required signing exists: it forces communication between account holders and prevents one person from draining the account without the other knowing.

Changing your signing structure

You can change from either/or to both-required (or vice versa) by contacting your bank. Call customer service, visit a branch, or use your online banking portal if the option is available. The bank will ask both account holders to confirm the change — some banks require both of you to sign a new signature card in person, while others allow one person to request the change online if both owners are verified on the account.

The new signing structure takes effect when ready for checks written after the change is processed. Any checks you wrote before the change still follow the old rules. If you have already written checks under the old structure, they will clear under the old signing requirements even if you changed the account the day after writing them.

When one account holder wants to prevent the other from signing

If you are concerned that the other account holder might write checks without your knowledge or permission, switching to both-required signing is the only structural protection the bank offers. However, this requires the other person's cooperation — they have to agree to the change, and most banks will not process it without confirmation from both owners.

If the other person refuses to agree and you believe they are misusing the account, your options are limited to the legal system, not the banking system. You can consult a family law attorney (if this is a spouse or domestic partner) or a general civil attorney about freezing the account, removing the other person, or other remedies. The bank itself cannot remove one owner without a court order or the consent of both owners.

Reporting unauthorized checks

If you discover that the other account holder signed a check without your knowledge or permission, report it to your bank when ready. Tell them the check number, the amount, the date it cleared, and who it was paid to. The bank will open an investigation and may reverse the transaction depending on how long ago it cleared and whether the funds are still traceable.

Banks have different timelines for disputing unauthorized transactions. For checks, you typically have up to 30 days from the date you receive your statement to report the problem, though some banks allow longer if you can show you did not have a reasonable opportunity to discover the fraud sooner. The sooner you report it, the better your chances of recovery.

Joint accounts and estate planning

The signing structure of your joint account has nothing to do with what happens to the money after one account holder dies. When one owner passes away, the account becomes the sole property of the surviving owner regardless of whether the account required one signature or two. The bank will freeze the account temporarily while they verify the death, then release it to the surviving owner.

If you want the account to go to someone other than the surviving joint owner, you need a will or a payable-on-death (POD) designation — the signing structure does not affect inheritance. Talk to an estate planning attorney if you want to change who inherits the account.

Frequently Asked Questions

Can I change the signing rules without telling the other account holder?

No. Most banks require both account holders to consent to a change in signing structure. Some banks allow one person to request the change online, but they will contact the other owner to confirm before processing it. If the other person refuses, the bank will not make the change.

What if we disagree about who should be able to sign checks?

If you and the other account holder cannot agree on the signing structure, you have three options: keep the account as is, close it and open separate accounts, or consult a family law attorney if this is a marital dispute. The bank will not take sides — they will only process changes that both owners agree to.

Does a check signed by the wrong person bounce?

Not automatically. A check signed by only one person on a both-required account may clear if the bank does not catch it. The check bounces only if the other owner disputes it after it clears, which triggers a reversal. If no one disputes it, the check stays cleared even though it violated the account rules.

Can I add a third person to the account to require three signatures?

You can add a third person as a joint owner, but most banks do not offer three-signature requirements. The signing structure is typically either/or (any owner can sign) or both-required (all owners must sign). Adding a third person on a both-required account means all three would have to sign every check, which is impractical for most households.

What if someone forges my signature on a check from our joint account?

Report it to your bank as fraud when ready. Forgery is different from unauthorized signing — it is a crime, and the bank has a separate process for it. You will need to file a police report as well. The bank will investigate and reverse the check, and law enforcement may pursue charges against the person who forged your signature.