How Does a Business Overdraft Work?

A business overdraft is one of the most common short-term finance tools available to UK businesses, and one of the most misunderstood. It is not a loan. It is a flexible facility that sits alongside your business current account, available when you need it and costing you nothing when you do not. This guide covers how it works, what it costs, and the situations where it earns its place.

What a business overdraft is

A business overdraft is a facility that lets you spend beyond your account balance, up to a pre-agreed limit. You pay interest on the amount you are overdrawn, not on the full limit, and once you are back in credit the facility sits dormant until you need it again.

That revolving nature is what sets it apart from a business loan. There is no fixed drawdown, no set repayment schedule, and no defined end date. You dip in when cash flow is tight, pay it back when the money comes in, and the facility resets automatically as long as your bank is comfortable with how you are running your account.

Arranged vs unarranged overdrafts

This distinction matters, and getting it wrong is expensive.

An arranged overdraft is one your bank has agreed in advance. You apply, the bank assesses your business and sets a limit and a rate, and you can draw on that facility whenever you need it. Interest is charged on the daily overdrawn balance, usually quoted as an EAR (Effective Annual Rate). Some accounts also charge a monthly or quarterly usage fee.

An unarranged overdraft is what happens when you go into the red without an agreed facility, or exceed your agreed limit. Banks charge significantly higher rates for unarranged borrowing. Some will decline the transaction outright. If they do allow it, the cost can accumulate quickly. The right approach is always to arrange the facility before you need it, not after the fact.

What a business overdraft costs

Costs vary between lenders, but the main components are:

• Interest on the overdrawn balance, typically between 5% and 20% EAR depending on your business profile and the lender

• An arrangement fee when the facility is first set up, often 1% to 2% of the limit or a fixed fee

• A monthly or quarterly maintenance fee on some accounts, charged regardless of whether you use the overdraft

• Substantially higher rates for any unarranged borrowing

The figure to focus on when comparing products is the EAR. It accounts for compounding and gives you a consistent basis for comparison. A lower headline rate with a hefty monthly fee can work out more expensive than a higher rate with no fee, depending on how you use the facility.

What a business overdraft is designed for

An overdraft works best for short-term cash flow gaps where the need is temporary and predictable. The most common use cases are:

• Bridging the gap between issuing invoices and receiving payment

• Covering payroll when a large customer payment is delayed

• Managing costs in a slow month for a seasonal business

• Handling unexpected expenses that fall between regular income cycles

If you know the money is coming in but need to bridge a short gap to get there, an overdraft is often the right tool. The key characteristic is that you expect to clear it within weeks or a few months. It is designed for temporary situations, not ongoing funding.

When an overdraft is not the right fit

An overdraft is not the answer to every funding need, and using it for the wrong purpose tends to be more expensive than the alternatives.

If you are funding a specific purchase such as equipment, a vehicle, or a fit-out, a business loan or asset finance gives you a fixed sum at a known cost over a defined term. That is more predictable and typically cheaper for larger amounts.

If your overdraft is never fully clearing from one month to the next, that is worth paying attention to. A revolving facility that stays permanently drawn is a signal that you have a structural working capital gap rather than a short-term cash flow issue. In that situation, a working capital loan or longer-term facility would give you a lower rate and a clear end date.

And if you are a new business without a trading history, overdraft limits can be lower than you might expect. Some lenders will not offer a facility until your account has been running for six months or more. Factor that in if you are choosing a business bank account with overdraft access in mind.

How to apply for a business overdraft

Most business current accounts let you apply for an overdraft through your online banking or business portal. For smaller facilities, typically under £25,000, the process is often quick. The bank reviews your account history and turnover and issues a decision within a few days.

For larger facilities, or if you are dealing with a traditional bank rather than a digital provider, expect more documentation. That can include management accounts, filed accounts, and a description of your business model. Limited companies may also be asked for a personal guarantee, particularly at the earlier stages of trading.

If you think you are likely to need an overdraft, it is worth applying before you need it rather than when you are already stretched. Banks are more willing to agree a facility when your account is healthy than when you are already in difficulty.

Not all business bank accounts include overdraft access, so it is worth checking this before you open one. You can compare business bank accounts on HowMuch to find providers that offer the facility.

Frequently asked questions

Is a business overdraft secured or unsecured?

Smaller limits are usually unsecured. Larger facilities, or those for newer businesses, may require a personal guarantee, particularly for limited companies where the bank has limited recourse to the directors' personal assets. Always check before agreeing to a facility.

Can a bank withdraw a business overdraft?

Yes. Overdraft facilities are reviewed periodically, and banks can reduce or withdraw them if your account conduct gives cause for concern. Frequently hitting your limit, going unarranged, or problems with other borrowing can all prompt a review. This is one reason not to rely on an overdraft as your sole source of working capital.

Does using a business overdraft affect my credit profile?

Using an overdraft does not in itself damage your credit profile. Consistently operating at or near your limit, or going unarranged, can be a flag for lenders assessing future applications. How you manage the facility matters as much as whether you use it.

What is the difference between a business overdraft and a business credit card?

Both provide short-term flexible credit, but they work differently. An overdraft is attached to your current account and is designed for cash flow management. A business credit card is a separate spending facility, often with rewards or expense tracking tools, and typically charges a higher rate on any balance you do not clear each month. The right choice depends on what you are using it for.

What happens if I go over my overdraft limit?

Going beyond your agreed limit puts you into unarranged borrowing territory. Most banks will either decline the transaction or charge significantly higher rates on the excess. Some charge a daily fee on top of the higher rate. Check your account terms so you know what applies to your account before it happens.