Overdrafts Explained: The Real Cost of Your Safety Net

An overdraft can feel like part of your bank balance rather than borrowing — it''s just there, ready to catch you when your account dips below zero. But an overdraft is a loan, and since UK banks moved to a single interest rate a few years ago, it''s often one of the more expensive ways to borrow, even though it doesn''t always feel that way.

Arranged vs unarranged

An arranged overdraft is one you''ve agreed with your bank in advance, with a set limit. An unarranged overdraft happens when you go over that limit, or over zero with no agreement at all — this is generally best avoided, as it can trigger extra fees and sometimes affect your credit file.

Why it''s more expensive than it looks

Since April 2020, UK banks have had to advertise overdrafts using a representative APR, much like a credit card. Many current account overdrafts sit somewhere around 35–40% APR — often higher than an average credit card. The difference is that overdraft interest is usually calculated daily and charged monthly, so it can be easy to lose track of how much you''re paying, especially if you dip in and out of it regularly rather than owing one fixed amount.

A rough example

If you''re £300 into your overdraft at roughly 39.9% APR for a month, that''s a small enough amount that the actual pounds-and-pence cost feels minor — a few pounds. The real cost adds up when an overdraft becomes a permanent fixture rather than an occasional buffer, because you end up paying that rate month after month on a balance that never really clears.

When an overdraft is fine — and when it isn''t

An overdraft used occasionally as a short-term buffer, cleared quickly when your next payslip lands, is a normal part of managing cash flow. It becomes a problem when it''s permanently maxed out, when you''re relying on it to cover everyday essentials every single month, or when you don''t actually know how much interest you''re paying.

Cheaper alternatives worth knowing about

• A 0% purchase or money transfer credit card, used carefully, can be far cheaper than sitting in an overdraft long-term.
• Some banks offer fee-free buffer zones (often £10–£50) before charges kick in — worth checking your own account''s terms.
• If debt has built up across several places, a free service like a debt charity or your bank''s own financial help team can talk through options with no judgement.

Action step

Check your current account''s overdraft APR today — it''s usually in your banking app or terms. If you''re regularly dipping into it, that''s a useful nudge to look at whether a cheaper form of short-term borrowing, or a small adjustment to your budget, could save you money.

This article is for general information only and doesn''t constitute financial advice. If you''re struggling with debt, free and confidential help is available from UK debt charities such as StepChange or National Debtline.