The overdraft is one of the most familiar — and most misunderstood — forms of borrowing in Britain. Because it lives inside your current account, it can feel like an extension of your own money rather than a loan. It is not. Used occasionally it is a handy safety net; relied on month after month it can quietly become an expensive habit. This guide explains how overdrafts work, the difference between arranged and unarranged, how charges changed after major reforms, and the cheaper options worth considering. This is general information, not financial advice.
What an overdraft is
An overdraft is a facility attached to a current account that lets you keep spending after your balance hits zero, up to a set limit — in effect, borrowing money from your bank. When you dip into it, you owe the bank, and interest is charged on the amount you use until you repay it.
The key mental shift is this: money in an overdraft is not your money. A balance of "−£150" means you owe £150, not that you have a buffer. Treating the overdraft as part of your spending power is how occasional use turns into a permanent overhang that is surprisingly hard to clear.
Overdrafts are a form of unsecured borrowing — there is no asset attached, unlike a mortgage. If you want the wider picture on how that compares with other loans, see our guide to secured versus unsecured loans.
An overdraft is the most convenient borrowing you will ever do — which is exactly why it is so easy to lean on without noticing the cost.
Arranged versus unarranged overdrafts
There are two ways to be overdrawn, and the distinction matters:
- Arranged (authorised) overdraft. A borrowing limit agreed with your bank in advance. You know it is there, you know the limit, and the terms are set out beforehand.
- Unarranged (unauthorised) overdraft. This happens when you spend beyond your balance with no arranged facility, or beyond your arranged limit. Historically, unarranged overdrafts came with steep fees and were a notorious source of unexpected charges.
For years, unarranged borrowing and a tangle of daily and monthly fees made overdrafts confusing and, for some, very costly. That is what prompted the regulator to step in.
How overdraft charges work now
In 2020, the Financial Conduct Authority (FCA) introduced major reforms to make overdraft pricing simpler and fairer. The headline changes were:
- A single interest rate. Banks must charge overdrafts using one simple annual interest rate, expressed as an APR, rather than a mix of daily fees, monthly fees and flat charges.
- No higher charges for unarranged use. Banks can no longer charge more for an unarranged overdraft than an arranged one.
- Clearer comparison. Because charges are now an APR, you can compare overdraft costs against other borrowing and between banks more easily.
The reforms made charges more transparent — but not necessarily cheap. Many banks settled on overdraft APRs that are high compared with other forms of credit, so an overdraft used for ongoing borrowing can still cost a lot. Understanding the rate is essential, and our guide to APR and the true cost of borrowing explains how to read it.
| Feature | Arranged overdraft | Unarranged overdraft |
|---|---|---|
| Agreed in advance? | Yes | No |
| Pre-2020 cost | Variable fees | Often very high fees |
| Since FCA reforms | Single APR | Same rate as arranged |
| Best used for | Short-term, planned gaps | Avoid where possible |
When an overdraft makes sense — and when it does not
An overdraft is a tool, and like any tool it suits some jobs better than others.
It can be reasonable for:
- Short-term, occasional shortfalls — covering a gap of a few days until payday.
- Genuine emergencies, where speed matters and the amount is small.
- A safety net you rarely actually use.
It is usually a poor choice for:
- Ongoing borrowing month after month, where the interest mounts up.
- Larger sums that would be cheaper to borrow another way.
- Anything you cannot realistically clear in the near future.
If you find yourself living in your overdraft — going overdrawn every month and never getting back to zero — that is a sign the underlying issue is a budget that does not balance, not a need for a bigger limit. Our guide to making a budget that works can help you find the gap, and a small emergency fund is the single best way to stop relying on an overdraft for surprises.
Cheaper alternatives
Before leaning on an overdraft for anything more than a brief, small shortfall, weigh up the alternatives:
- An emergency fund. Even a modest savings buffer removes the need to borrow for surprises at all.
- A lower-cost loan or credit option. For a planned, larger expense, a personal loan may carry a much lower rate than an overdraft — compare the total cost across lenders before deciding.
- A 0% purchase credit card, used carefully and cleared within the interest-free period (this requires discipline and is not for everyone).
- Talking to your bank. If you are regularly overdrawn, your bank may be able to help; under FCA rules, banks are expected to identify and support customers showing signs of financial difficulty.
If overdraft debt has become persistent, free and impartial help is available from MoneyHelper and Citizens Advice, and debt charities such as StepChange can advise at no cost. Seeking help early gives you more options.
The bottom line
An overdraft is borrowing dressed up as part of your current account, and that disguise is its main danger. There are two kinds — arranged, agreed in advance, and unarranged, which you should avoid — and since the FCA's 2020 reforms both are charged at a single, comparable APR, with no penalty premium for going unarranged. That makes the cost clearer but not low: overdrafts can be an expensive way to borrow over time. Use one only for short, small gaps, build a buffer so you need it less, and if you are permanently overdrawn, treat it as a budgeting signal and seek free help.