What Is a Business Overdraft and How Does It Work?
Business Overdraft
Australian business · Cashflow · Account-linked credit
A business overdraft is a revolving line of credit attached to a business transaction account. This guide explains how the account goes into debit, rates and line fees, repayments through deposits, secured and unsecured options, eligibility, limit sizing, excess drawings, review risk and when a separate line of credit may fit better.
Quick Answer
A business overdraft is a type of revolving line of credit linked to a business transaction account. It lets the account go below zero up to an approved limit. Interest is usually charged on the debit balance, while line, account and excess-drawing fees may also apply.
What is a business overdraft in Australia?
A business overdraft is a type of revolving line of credit attached to a business transaction account. It allows the account to go below zero up to an approved limit, usually to cover short cashflow timing gaps.
In plain English, it is a buffer attached to the account your business uses for deposits and payments. The business can draw into the overdraft when payments leave before customer money arrives, then reduce the drawn balance when receipts land. Business.gov.au describes a finance facility as an arrangement from a financial institution that can include a bank account, short-term loan or overdraft, and separately defines an overdraft facility as letting a business withdraw more than the account balance.
This guide focuses on business-purpose overdrafts, not personal overdrafts. If you only need the definition, start with the Switchboard overdraft glossary; if you are comparing flexible cashflow facilities, use the sections below to decide whether an overdraft, line of credit or another working-capital product fits better.
How does a business overdraft work?
A business overdraft works by linking an approved credit limit to a transaction account, allowing the account to move into debit and then recover as customer receipts or other deposits arrive.
The key moving parts are the transaction account, approved limit, debit balance and deposits. If an $80,000 limit is approved and the account is $25,000 overdrawn, interest is usually calculated on the $25,000 debit balance rather than the full limit. Line, annual or account fees may still apply while part or all of the limit is unused.
Do business overdrafts have fixed repayments?
Business overdrafts commonly have no fixed principal repayment schedule. Deposits into the linked transaction account reduce the overdrawn balance automatically, although interest, fees, review conditions and any requirement to bring the account back within limit still apply.
A separate line of credit is also revolving credit, but it normally sits outside the operating account and may have different draw, minimum-payment, term and review settings.
A wholesale business has a supplier invoice due on Tuesday and customer receipts expected on Friday. The overdraft covers the three-day timing gap. When the customer pays, the deposit reduces the debit balance and the account returns close to nil or positive. That is the cleanest use case: short, documented and self-clearing.
What are business overdraft interest rates, fees and costs?
A business overdraft can cost more than its headline interest rate because line fees, transaction-account fees, establishment costs and excess-drawing charges may apply as well.
What is a business overdraft interest rate?
A business overdraft interest rate is the annual rate applied to the account's debit balance. There is no single standard rate: secured and unsecured pricing can differ significantly, and the final rate depends on the limit, security, credit profile, banking conduct and lender policy.
For market context only, the RBA F5 indicator lending rates file recorded small business variable overdraft at 10.76% p.a. and small business variable term lending at 9.00% p.a. for 31 May 2026, published 5 June 2026. These are dated indicator series, not borrower quotes and not fee-inclusive comparisons.
How is business overdraft interest calculated?
A simple daily-interest estimate is the debit balance multiplied by the annual interest rate, multiplied by the number of days overdrawn, divided by 365. The lender's contract controls the actual day count, compounding method, default rate and charging frequency.
debit balance × annual rate × days overdrawn ÷ 365
Assume the account is $25,000 overdrawn for 14 days at 10.76% p.a. solely to demonstrate the calculation. $25,000 × 0.1076 × 14 ÷ 365 is approximately $103 before line, account or other fees. The 10.76% figure is the dated RBA indicator above, not a rate an applicant will receive.
| Cost component | How it usually works | What to check |
|---|---|---|
| Interest on debit balance | Usually calculated while the transaction account is below zero. | Check the variable rate, calculation method, charging frequency and default rate. |
| Line or facility fee | May be charged on the approved limit or another basis even if the limit is not fully used. | Ask whether it is fixed, percentage-based, monthly, quarterly or annual. |
| Establishment or review fee | May apply when the facility is opened, increased, renewed or restructured. | Check the upfront amount and whether further fees apply at annual review. |
| Excess-drawing cost | Extra interest or fees may apply if the account exceeds the approved limit or a payment is honoured outside it. | Check whether transactions are declined, approved at a higher rate, or treated as a default event. |
| Transaction-account fees | The linked operating account may have its own monthly, transaction or service charges. | Compare the total banking package rather than the overdraft rate alone. |
| Security and legal costs | A secured facility may involve valuation, registration, legal or discharge costs. | Confirm which costs are payable upfront, at review and on exit. |
What are current advertised business overdraft rates, fees and limits?
A dated product example can help show the difference between an indicator rate and an actual advertised facility. CommBank's page was verified on 7 July 2026 and labels the figures below as current from 15 May 2026. They are one lender's starting rates and product settings, not a market average, Switchboard quote or rate an applicant will receive.
| Published item | Published figure | Important context |
|---|---|---|
| Unsecured variable rate | From 14.80% p.a. | Individual pricing depends on the applicant and is confirmed in the offer. |
| Secured variable rate | From 8.75% p.a. | Residential, rural or commercial property security is required for the advertised secured option. |
| Line fee | 1.70% p.a. | Charged for keeping the approved overdraft available, in addition to debit interest. |
| Unsecured limit | $2,000 to $250,000 | Subject to eligibility and credit assessment. |
| Existing-customer application | Up to 10 minutes; instant decision and funds within minutes if eligible | Not a universal approval time and subject to the bank's eligibility and suitability criteria. |
Current product example: CommBank business overdraft, verified 7 July 2026; the page labels its figures as current from 15 May 2026.
What would a $50,000 business overdraft cost for 30 days?
Using the RBA's dated 10.76% p.a. small-business variable-overdraft indicator solely as a calculation input, a $50,000 debit balance held for 30 days would produce about $442 of interest before line fees, account fees or other charges: $50,000 × 0.1076 × 30 ÷ 365. This is an illustration, not an available or typical borrower rate.
Is business overdraft interest tax deductible?
Interest may be deductible to the extent the overdraft is used to earn assessable business income. Private drawings or mixed use can require apportionment, and establishment, line and borrowing fees may not be treated in exactly the same way as ordinary interest. Keep records showing what each draw funded and obtain advice from a registered tax agent.
Tax guidance: Australian Taxation Office, interest expenses.
What happens if you exceed a business overdraft limit?
The bank may decline the transaction, allow an excess drawing and charge additional interest or fees, or treat the breach as a review or default event under the contract. Payroll, direct debits and supplier batches should be monitored against both the approved limit and upcoming interest or fee debits.
What is an unapproved or unarranged business overdraft?
An unapproved or unarranged overdraft occurs when the transaction account goes below zero without an approved facility, or exceeds the approved overdraft limit. The bank may decline payments, charge higher debit interest or fees, require the excess to be cleared immediately, or treat the conduct as a credit or default issue. It should not be relied on as a substitute for an arranged business overdraft.
Who qualifies for a business overdraft?
A business is more likely to qualify when it has stable trading, clean account conduct, a sensible limit request and a clear business purpose for a short-term cashflow gap.
What documents are needed for a business overdraft?
Lenders may request ABN or ACN details, recent business bank statements, revenue history, existing-debt information, tax position, financial statements, BAS, forecasts, security details and information about directors or guarantors. Existing-bank digital applications may start with less paperwork because the bank already holds account data.
For a broader view of assessment, read Switchboard's guide to what lenders check before approving a business loan.
Can a sole trader get a business overdraft?
Yes. A sole trader can apply for a business overdraft on a business transaction account, although the bank may assess the owner's personal credit and require a personal guarantee because the individual and business are not separate legal entities. The application still needs sufficient trading cashflow, acceptable account conduct and a realistic limit.
Can a startup get a business overdraft?
A pre-revenue startup will usually find an overdraft difficult because there is no established deposit pattern or operating cashflow for the bank to assess. A newer trading business may have options after it can show consistent account activity, sales and a clear repayment cycle, or where acceptable security supports the request. Minimum trading periods and security rules vary by lender.
Can you get a business overdraft with bad credit?
It may be possible, but active defaults, repeated dishonours, recent arrears or unresolved tax debt can reduce the limit, increase the price or stop approval. Lenders distinguish between an older resolved issue and current conduct problems. A targeted eligibility review before a formal application can reduce unnecessary credit enquiries.
How do you apply for a business overdraft?
Start by estimating the largest genuine cashflow gap and how quickly normal receipts should clear it. Then compare an overdraft with a separate line of credit, gather recent bank statements and financial information, disclose existing debts and tax obligations, and review the lender's rate, line fee, security, guarantee, review and over-limit terms before accepting an offer.
- Measure the cashflow gap and choose a realistic limit.
- Compare secured, unsecured and separate line-of-credit structures.
- Gather the requested bank statements, BAS, financials and identification.
- Submit the application and respond to credit questions.
- Read the offer and facility terms before the limit is activated.
How fast can a business overdraft be approved?
An eligible existing-bank digital application may be assessed quickly, sometimes on the same day, because the bank already holds transaction data. New-to-bank, secured, larger or more complex applications can take several business days or longer where financial statements, guarantor checks, valuation or legal documents are required. Published lender timeframes are not guarantees.
Current lender example, not a universal rule: CommBank says an existing customer application can take up to 10 minutes and may receive an instant decision with funds within minutes if eligible. Its published approval indicators also say applicants are more likely to be approved where they have not been overdrawn or in arrears in the past 3 months, bankrupt in the past 5 years, or in collections in the past 6 months. These are product-specific criteria shown on the page and verified 7 July 2026; the page labels its figures as current from 15 May 2026.
Can a lender ask for a personal guarantee?
Yes. A lender may require one or more directors or business owners to guarantee repayment even when the overdraft is described as unsecured. A guarantee can create personal liability if the business defaults, so the guarantor should understand any cap, continuing-security wording, indemnity, enforcement rights and release process and obtain independent legal advice where appropriate.
Broker-observed, indicative only
What gets a business overdraft approved or declined?
Indicative only. As of July 2026, based on Switchboard broker experience across business cashflow and revolving-credit enquiries. This is not a quote, offer, approval indication, savings claim, rate promise or recommendation.
Stronger-fit overdraft files usually have clean account conduct, stable deposits, a clear short-term cashflow gap and a limit request that matches the gap rather than the largest amount available.
An existing bank may be able to assess an eligible digital application quickly. New-to-bank, larger or secured applications can take longer where financial statements, guarantor checks, property security, valuation or legal documents are needed.
Decline or reframe patterns include recent over-limit conduct, unresolved defaults, active tax arrears without a plan, trading losses with no recovery evidence, existing facilities already at limit, or using the overdraft as permanent loss funding.
These observations are indicative only and are not a loan quote or approval guide. Lenders assess security, conduct, revenue, existing debt, guarantors and the purpose of the facility. Rates, fees and approval timeframes can change and must be confirmed from the live lender offer.
Secured vs unsecured business overdraft
A secured business overdraft uses an asset or other security to support the facility, while an unsecured business overdraft relies more heavily on business conduct, cashflow, guarantees and credit policy.
Security can affect pricing, limit size, approval requirements and what happens if the business defaults. A secured facility may use property, business assets or other acceptable collateral. An unsecured facility may still require director guarantees, even though no specific asset is being taken as security. The key distinction is whether the lender takes specific asset security; an unsecured facility can still include director guarantees or a general security arrangement.
| Factor | Secured business overdraft | Unsecured business overdraft |
|---|---|---|
| Security | ✓ Usually supported by property, business assets or other accepted security. | ✗ No specific asset security, though guarantees may still apply. |
| Typical limit shape | Can suit larger limits where the security position supports the facility. | Often smaller or more tightly policy-driven because the lender has less collateral. |
| Pricing tendency | May price lower where security reduces lender risk. | May price higher because the lender relies more on conduct and cashflow. |
| Documents | May require valuation, security documents and guarantor checks. | May rely more on bank data, trading history, tax position and director details. |
| Speed | Can take longer if security, valuation or legal documents are needed. | Can be faster where the lender can assess digitally and policy is met. |
| Best fit | Larger or recurring working-capital buffers with acceptable security. | Smaller short-term gaps where the business has clean conduct and stable deposits. |
Can a business overdraft be reviewed or called in?
A business overdraft can be reviewed, reduced or required to be repaid if the facility terms allow it, so the offer letter and ongoing conduct matter as much as the limit.
The practical risk is false comfort. A limit can feel permanent when it appears in the transaction account every day, but many overdrafts are reviewed periodically and may be subject to conditions, reporting, repayment-on-demand wording or default triggers. Moneysmart's overdraft factsheet, although consumer-focused and older, also flags the need to consider how an overdraft would be repaid if repayment is required on demand.
Terms to check before signing: review date, annual renewal process, repayment-on-demand wording, over-limit treatment, default interest, financial information requests, guarantor obligations, security documents and whether the lender can reduce the approved limit.
Switchboard's guide to safe use of revolving credit is the natural next read if the facility will be used as a recurring cashflow buffer.
Business overdraft vs line of credit: what is the difference?
A business overdraft is the transaction-account version of revolving credit, while a business line of credit is commonly a separate facility with its own draw, repayment and account structure.
Neither is universally better. Choose based on how money should be accessed, how repayments should occur, the full fee structure and how much control the business needs over the facility. The complete business line of credit guide covers standalone, non-bank, secured and unsecured line structures in detail.
Is a business overdraft cheaper than a business credit card?
An overdraft can have a lower debit interest rate than many business credit cards, particularly where security supports the facility, but it is not automatically cheaper. A line fee, transaction-account fee, establishment cost and the length of time the balance remains overdrawn can outweigh the headline-rate difference. CommBank currently describes its overdraft rates as lower than most business credit cards, but the correct comparison is the total dollar cost for the expected usage pattern.
| Facility | How access and repayment work | Best fit and main caution |
|---|---|---|
| Business overdraft | Attached to the transaction account; payments take the account into debit and deposits automatically reduce the balance. | Short account-timing gaps. Check line fees, excess drawings, annual review and repayment-on-demand terms. |
| Business line of credit | Usually a separate revolving facility; the business draws funds and repayments restore the amount available. | Recurring or uncertain cashflow needs requiring clearer draw control. Check draw, facility, expiry and minimum-repayment terms. |
| Working capital loan | A lump sum is advanced and repaid under a fixed weekly or monthly schedule. | A known one-off funding amount. Repayments continue even if the cashflow benefit arrives later than expected. |
| Business credit card | Used for eligible card purchases with a statement cycle and minimum payment; cash advances may have separate costs. | Smaller card-based expenses and short payment cycles. Limits may be lower and cash access can be expensive. |
Is a business overdraft good for cashflow?
A business overdraft can be good for a short timing gap that opens and closes inside the transaction account. It is usually a poor fit when the balance remains permanently drawn or the funding need has a fixed, longer repayment horizon.
Use the account cycle as the test. If known receipts will reduce the balance soon, the overdraft may be well matched. If the need is a defined lump sum, compare a working capital loan; if the gap follows unpaid invoices, compare invoice finance.
How do you clear or reduce a business overdraft?
Deposits into the linked transaction account normally reduce the overdrawn balance automatically. To clear it deliberately, direct customer receipts into the account, stop non-essential new drawings, set a weekly reduction target and use a cashflow forecast to identify when the balance should return to nil. If ordinary trading receipts cannot materially reduce the balance, discuss restructuring part of it into a term facility rather than relying on a permanently drawn overdraft.
Good overdraft pattern
The business draws for a short period, receipts are already expected and the balance returns to nil or positive before the next cycle.
Reframe pattern
The overdraft sits near its limit every month, interest accumulates and the account never truly recovers after customer receipts land.
What can a business overdraft be used for?
A business overdraft is usually used for short-term operating expenses such as supplier bills, payroll timing, stock purchases, BAS timing or seasonal cashflow gaps.
The cleanest uses are tied to a specific receipt cycle. For example, the business has invoices issued, a purchase order confirmed, seasonal revenue expected or predictable daily card settlements coming through. The weaker uses are vague, permanent or loss-covering. If the need is broader than an account timing gap, compare Switchboard's working capital loans page before choosing the structure.
A retailer buys extra stock before a known seasonal trading period. The overdraft is drawn for the order, then paid down as stock sells and card receipts arrive. This works best when the purchase cycle and repayment cycle are visible before the facility is used.
How big should the overdraft limit be?
The overdraft limit should match the largest realistic short-term cashflow gap, not the biggest amount the business can possibly borrow.
How much can you borrow with a business overdraft?
Limits vary widely by lender, security, turnover and account conduct. As one current advertised example, CommBank publishes unsecured overdraft limits from $2,000 to $250,000 and secured overdraft limits from $2,000, subject to assessment. A sensible limit should still be based on the peak short-term cashflow gap and the business's ability to return the account toward nil or positive.
Start with the cash conversion cycle: when money leaves, when money comes back, what buffer is needed if receipts run late, and how much headroom is needed before the account breaches the limit. A sensible limit usually has a clear use case, clear repayment source and enough breathing room to avoid accidental over-limit conduct. Switchboard's guide to setting a business line-of-credit limit maps the same logic in more detail.
A contractor has a $100,000 overdraft that sits between $85,000 and $100,000 drawn every month. Customer receipts reduce the balance briefly, but payroll and supplier payments push it back to the limit. That is no longer a short timing gap. The business may need a different facility, repayment plan, invoice finance review or pricing and margin review.
What legal protections apply to business overdrafts?
Business-purpose overdrafts can sit outside the National Credit Act consumer-credit framework, so borrowers should understand the commercial loan protections and dispute pathways before signing.
ASIC INFO 101 says the consumer credit test turns on whether the credit is predominantly for personal, domestic or household purposes, with predominantly meaning more than 50%. If credit is not predominantly for those purposes, it is not regulated under the National Credit Act. ASIC INFO 207 separately says commercial loans, including small business loans, have a lower level of legal protection than consumer loans, although ASIC Act protections can still matter.
ASIC also notes that AFCA can resolve eligible commercial-lending complaints from small businesses, with AFCA's rules defining a small business as a primary producer or another business with fewer than 100 employees. Access depends on the financial firm, complaint type and AFCA limits. For broader product-family context, see Switchboard's business loans page.
When should you choose another cashflow product?
Choose another cashflow product when the need is longer-term, asset-backed, invoice-specific, card-specific or too persistent for an overdraft to clear naturally.
Can you convert a business overdraft into a term loan?
It may be possible to refinance or restructure a persistently drawn overdraft into a term loan, but the conversion is not automatic. The lender will usually reassess serviceability, credit, security and the reason the balance has not cleared. A term structure can create a defined repayment schedule, but establishment, discharge, valuation or legal costs may apply and the business still needs a credible repayment source.
A flexible overdraft can be useful, but it is not the only revolving option and it is not a fix for a business model that is losing money. If the business wants a facility for repeated draw-and-repay cycles, compare a flexible line of credit. If the need is a defined working-capital injection, compare a working capital loan. If the gap is created by slow-paying invoices, invoice finance may be more directly matched to the receivable.
Use an overdraft when
The gap is short, tied to the transaction account and expected to clear when known receipts arrive.
Look elsewhere when
The balance never clears, the funding need has a fixed term, or the facility is being used to cover ongoing losses.
A business overdraft is revolving credit linked to a business transaction account. It can work well for short, recurring cashflow gaps that clear when customer receipts arrive, but interest, line fees, guarantees, annual reviews and repayment-on-demand terms can materially change the risk and total cost.
Best test: does the account regularly return to nil or positive? If the balance remains permanently overdrawn, a line of credit, working capital loan or longer-term facility may be a better structure.Frequently asked questions
A business overdraft is a revolving line of credit linked to a business transaction account. It lets the account go below zero up to an approved limit, generally to cover short cashflow timing gaps.
The bank approves a limit on the transaction account. Payments can take the account into debit up to that limit, and later deposits automatically reduce the overdrawn balance. Interest is generally charged on the debit balance, while line and account fees may also apply.
An overdraft is the transaction-account form of revolving credit, while a business line of credit is commonly a separate facility. Read the business line of credit guide for the standalone structure, limits, repayments, fees and application process.
Interest is usually charged on the debit balance rather than the full approved limit. A line or facility fee may still be charged on the limit, and transaction-account or excess-drawing fees can also apply.
Possible costs include establishment, line, account, annual-review, valuation, legal, default and excess-drawing fees. Compare the total annual dollar cost and contract terms, not only the debit interest rate.
Yes. An unsecured overdraft does not use a specific asset as security, although the lender may still require director guarantees and will assess revenue, credit, debts, tax position and account conduct.
Yes. A lender may require directors or business owners to guarantee repayment even where the overdraft is described as unsecured. A guarantor can become personally liable if the business defaults, so guarantee and release terms should be reviewed carefully.
Lenders may check recent bank statements, financial statements, BAS, tax position, ABN or ACN details, trading history, existing debts, forecasts, security and information about directors or guarantors. Existing-bank digital applications may start with less paperwork because the bank already holds account data.
Yes, if the contract permits it. Check annual review dates, repayment-on-demand wording, default triggers, information requests, over-limit rules and the lender's right to reduce or cancel the limit before treating the facility as permanent.
A separate line of credit may fit better when the business wants funds outside the operating account, clearer draw controls, broader bank and non-bank options or a facility designed for repeated draw-and-repay cycles. Compare fees, repayments, security and review terms across both structures.
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