What actually happens when you overdraft

An overdraft occurs when you spend more money than you have in your checking account, and your bank covers the difference. The moment your balance goes negative, you have overdrafted. This can happen in seconds—a debit card purchase, an ATM withdrawal, a check that clears, or an automatic bill payment can all push you below zero instantly.

The bank does not have to let this happen. Many banks now offer overdraft protection, which means they will cover the shortfall. But covering it is not free: you pay an overdraft fee, usually between $25 and $35 per transaction, though some banks charge more. Some banks also charge a daily fee if your account stays negative.

You do not need to sign up for overdraft protection to overdraft. For debit card and ATM transactions, federal rules say banks can only charge overdraft fees if you have opted in. For checks and automatic payments, banks can charge overdraft fees without your permission.

Key Takeaways

  • An overdraft happens the moment your balance goes negative, whether from a debit purchase, check, ATM withdrawal, or automatic payment.
  • Debit card and ATM overdrafts require you to have opted into overdraft protection; checks and automatic payments can overdraft your account without your consent.
  • Each overdraft transaction typically costs $25 to $35, and some banks charge an additional daily fee while your account remains negative.
  • Your bank may cover multiple overdrafts in a single day, stacking fees on top of each other, even if the total overage is small.
  • Overdraft fees are separate from any late fees or penalties you may owe to the person or company you were trying to pay.

How transactions trigger overdrafts in different orders

The order in which your bank processes transactions matters, because it determines how many overdraft fees you pay. Banks do not always process transactions in the order you made them. Many banks process checks and automatic payments first, then debit card transactions, even if you swiped your card before the check cleared. This practice, called reordering, can create overdrafts that would not have happened if transactions had cleared in the order you made them.

Example: You have $100 in your account. You make a $60 debit card purchase, then a check for $50 clears. If the bank processes the check first, your balance drops to $50, then the debit card purchase brings it to negative $10—one overdraft fee. If the bank processes in the order you made them, the debit card brings you to $40, then the check brings you to negative $10—still one fee. But if you made multiple small debit purchases and a large check, reordering can stack fees quickly.

Some banks have stopped reordering transactions and now process them in the order received. Others still reorder. Check your bank's transaction processing policy in your account agreement or by calling customer service.

When your bank covers the overdraft automatically

If you have overdraft protection linked to another account—a savings account, money market account, or line of credit—your bank will automatically transfer money from that account to cover the shortfall. This prevents the overdraft fee, but you may pay a transfer fee instead, which is usually smaller ($1 to $10). You will also owe the money back to the linked account.

If you do not have a linked account and have not opted into overdraft protection for debit cards and ATMs, the transaction may simply be declined. Your card will not work, and you will not overdraft. For checks and automatic payments, the bank will cover the overdraft and charge you a fee, because you cannot opt out of overdraft coverage for these transactions.

Some banks offer a grace period—usually one business day—before charging an overdraft fee. If you deposit money or transfer funds in time, the fee may be waived. Ask your bank whether this applies to your account.

How overdraft fees stack up in a single day

Banks can charge one overdraft fee per transaction, not one fee per day. If you overdraft your account five times in one day—five separate debit card purchases, for example—you could face five overdraft fees, totaling $125 to $175. This happens even if the total amount you overspent was only $20.

Some banks cap the number of overdraft fees they will charge in a single day, usually at three to five fees. Others do not. Check your account agreement or call your bank to find out the limit, if any.

The fees compound the problem: if you overdraft by $20 and pay a $35 fee, your balance is now negative $55. If you do not deposit money immediately, you may face a daily fee for maintaining a negative balance, which can be $5 to $10 per day. After a week, that $20 overage could cost you $70 or more in fees.

What happens if you stay overdrawn

If your account stays negative for more than a few days, your bank may close your account and send the balance to a collection agency. The bank reports the closed account to ChexSystems, a banking history database, which can make it harder to open a new account elsewhere for up to five years. Some banks will not open an account for someone with a recent closure due to overdraft.

You are still responsible for the negative balance even after the account closes. The bank or collection agency can pursue you for the money, and the debt can appear on your credit report. If you ignore it, they may sue and garnish your wages or bank accounts.

If you realize you have overdrawn, contact your bank immediately. Many banks will waive one or two overdraft fees per year if you ask, especially if you have been a customer for a long time or if the overdraft was small. There is no harm in asking.

Overdrafts versus NSF checks

An NSF check (non-sufficient funds) is a check that bounces because there is not enough money in the account to cover it. If your bank does not have overdraft protection, the check will be returned to the person who deposited it, marked NSF. You will not pay an overdraft fee to the bank, but you will likely pay an NSF fee to the person or business that tried to cash the check—often $25 to $50.

If your bank does have overdraft protection and covers the check, you pay the overdraft fee to the bank instead. Either way, you owe the money. The difference is who charges you and how much.

If you write a check knowing you do not have the funds, that is check fraud in most states, even if you plan to deposit money before it clears. Intentionally writing bad checks can result in criminal charges.

How to stop overdrafting

The simplest method is to keep a buffer in your account—money you do not spend, so your actual balance never reaches zero. A $100 to $200 buffer catches most small mistakes and prevents overdraft fees.

Set up account alerts through your bank's app or website. Most banks allow you to receive a text or email when your balance drops below a certain amount—$50, $100, or whatever you choose. This gives you time to deposit money before you overdraft.

If you have opted into overdraft protection for debit cards and ATMs, consider opting out. Without it, your card will simply be declined if you do not have enough money, which is inconvenient but free. You cannot opt out of overdraft protection for checks and automatic payments, but you can avoid writing checks and set up automatic payments only for bills you know you can cover.

Track your spending in real time using your bank's app or a budgeting tool. Many people overdraft because they do not know their current balance—they remember a deposit but forget a pending transaction. Checking your balance before every purchase takes 10 seconds and can save you $35.

Frequently Asked Questions

Can a bank charge me an overdraft fee if I did not opt in?

For debit cards and ATM withdrawals, no—you must opt into overdraft protection first. For checks and automatic bill payments, yes—banks can charge overdraft fees without your permission. If you did not opt in to debit card overdraft protection, the transaction should be declined instead.

What is the difference between an overdraft fee and a daily fee?

An overdraft fee is charged once per transaction that causes your account to go negative, usually $25 to $35. A daily fee is charged for each day your account stays negative, usually $5 to $10. You can pay both in the same month if you overdraft and do not deposit money quickly.

Will an overdraft hurt my credit score?

An overdraft itself does not appear on your credit report and does not hurt your score. However, if your account goes to collections or the bank sues you, that will appear on your credit report and damage your score. Paying the overdraft quickly prevents this.

Can I dispute an overdraft fee?

Yes. Contact your bank and explain why you believe the fee was unfair—for example, if the bank reordered transactions or if you were not notified of a pending charge. Banks often waive one or two fees per year, especially for long-time customers. There is no may provide, but asking costs nothing.

What happens if I ignore an overdraft and do not pay it back?

Your bank will close your account and may send the debt to a collection agency. The agency can sue you, garnish your wages, or freeze your bank accounts. The debt can stay on your credit report for up to seven years, making it harder to borrow money or open new accounts.