What Is a Line of Credit? How It Works, With a Real Example

Every January, Harbor & Pine Landscaping’s revenue drops to almost nothing. Snow covers the lawns they’d otherwise be mowing, nobody’s calling about hardscaping quotes, and the crew still needs to be paid something to keep them from taking jobs elsewhere before spring rehiring gets harder. Every June, the opposite problem hits — more mowing, planting, and installation work than the crew can keep up with, and cash pouring in faster than it goes out. Same business, same twelve months, two completely different cash flow realities.

A term loan doesn’t fit this pattern well — it hands over a lump sum on day one and charges interest on the whole thing whether it’s needed in January or sitting unused in July. What Harbor & Pine actually needed was financing that could flex with a business that doesn’t earn evenly across the year, which is exactly the problem a line of credit is built to solve.

This guide covers what a line of credit actually is, exactly how draws, interest, and repayment work using Harbor & Pine’s real year as a running example, how it compares to a term loan and a business credit card, the secured-vs-unsecured decision, and what lenders actually look at before approving one.

(A quick note: this article explains how business lines of credit generally work. Rates, limits, and terms vary significantly by lender and change with broader interest rate conditions — this isn’t financial advice, and current offers are worth comparing directly with a bank or lender before deciding.)

What Is a Line of Credit?

A line of credit is a flexible, revolving form of financing that gives a business access to a set maximum amount of credit — a credit limit — which it can draw from as needed, repay, and draw from again, similar in structure to a credit card but usually with lower rates and, often, cash-access flexibility a credit card doesn’t offer. The defining feature is right there in the word “revolving”: unlike a term loan, which delivers one lump sum that gets repaid on a fixed schedule and is done, a line of credit’s available balance replenishes as you repay what you’ve drawn — the same $50,000 limit can be drawn, repaid, and drawn again many times over the life of the account.

Interest is charged only on the amount actually drawn and outstanding — not on the full approved limit. A business approved for $50,000 that never draws a dollar of it pays nothing in interest (though some lenders charge a small maintenance or unused-line fee, covered below), which is the core trade-off that makes a line of credit so well-suited to uneven, seasonal, or unpredictable cash flow needs. Bank of America’s own explainer on how business lines of credit work covers this same revolving mechanic from a lender’s perspective, which is worth reading alongside this guide if you’re comparing offers from your own bank.

Common Fees That Aren’t Interest

Interest is the headline cost, but it’s rarely the only one. Depending on the lender, a line of credit can also carry:

• An origination or draw fee, charged once when the line is opened or each time funds are drawn, rather than continuously like interest.
• An annual or maintenance fee, charged simply for keeping the line open regardless of use.
• An unused-line fee, charged on the undrawn portion of the limit — a real cost for a business that secures a large limit “just in case” and rarely taps it.
• An early closure fee, if the line is paid off and closed before a minimum term the lender expects.

None of these are hidden exactly — they’re generally disclosed in the agreement — but they’re easy to skip past when comparing offers primarily by interest rate. Two lines with identical rates can have meaningfully different total costs once these fees are factored in, which is exactly why reading the full business loan agreement rather than just the advertised rate matters.

How a Line of Credit Actually Works: Harbor & Pine’s Year

Numbers make the mechanics concrete faster than a definition does. Here’s a simplified, illustrative year for Harbor & Pine Landscaping, approved for a $50,000 line of credit at a hypothetical 10% annual interest rate (real rates vary by lender and creditworthiness — this figure is chosen purely to make the math easy to follow).

Across the whole year, Harbor & Pine paid roughly $667 in total interest — only on the months and amounts actually borrowed — to bridge two predictable slow stretches, then had the full limit available again the moment each balance was repaid. A term loan for the same purpose would have delivered the cash on day one and charged interest on the full balance through July, August, and September too, even though the business had no use for it, and needed it there, during those particular months.

Line of Credit vs. Term Loan vs. Business Credit Card

These three get compared constantly because they solve overlapping problems in different ways:

The short version: if the need is a specific one-time purchase with a clear price tag — buying a building, a fleet of vehicles, acquiring a competitor — a term loan usually fits better, since it’s structured for exactly that. If the need is smaller, recurring purchases with a grace period, a business credit card can work well. If the need looks like Harbor & Pine’s — an amount that varies month to month and isn’t fully known in advance — a line of credit is usually the more efficient fit, because you’re not paying for money you’re not using. NerdWallet’s comparison of business loans and lines of credit walks through several more scenario-based examples if you’re still weighing which fits your specific situation.

Also worth knowing: this same revolving-vs-lump-sum distinction shows up well beyond small business financing — banks themselves borrow from each other short-term using a similar revolving concept, sometimes called call money, which is a useful parallel if you’ve ever wondered whether “borrow only what you need, when you need it” is a small-business-specific idea or something baked more fundamentally into how lending works at every scale. It’s the latter.

Secured vs. Unsecured Lines of Credit

Lenders offer both, and the difference comes down to whether the business has pledged a specific asset the lender can claim if the line isn’t repaid:

• A secured line of credit is backed by collateral — commonly accounts receivable, inventory, equipment, or real estate — which generally allows for a higher credit limit and a lower interest rate, since the lender’s risk is reduced by having a specific asset to fall back on.
• An unsecured line of credit isn’t backed by a specific asset, which usually means a lower limit, a higher rate, and a heavier reliance on the business’s credit history and revenue to qualify — though many unsecured lines still require a personal guarantee from the business owner, which is a different form of exposure than pledging a specific asset.

Since collateral, loan-to-value ratios, and how lenders actually decide how much a pledged asset is worth are deep topics in their own right, we cover them in full in our dedicated guide to what collateral is — worth reading before you’re sitting across from a loan officer deciding whether securing your line is worth the trade-off.

What Determines Your Credit Limit and Interest Rate

Rates and limits vary enough by lender, location, and broader interest-rate conditions that citing a specific number here would likely be outdated by the time you’re comparing real offers — but the factors lenders weigh are consistent:

• Time in business. Most lenders want to see at least six months to two years of operating history before extending a line of credit, since a longer track record gives them more revenue data to underwrite against.
• Revenue and cash flow consistency. Lenders generally want to see revenue that comfortably supports the payments, and consistent (even if seasonal and predictable, like Harbor & Pine’s) cash flow tends to underwrite better than sporadic, unpredictable revenue.
• Personal and business credit score. Both typically factor in, especially for a newer business without an extensive business credit history of its own.
• Whether the line is secured. As covered above, pledging collateral generally improves both the rate offered and the maximum limit available.
• The lender type. Traditional banks often offer the lowest rates but the strictest qualification standards and slowest approval; online and alternative lenders tend to approve faster and more leniently, generally in exchange for a higher rate.

Comparing current business bank options directly, rather than relying on advertised rates alone, is worth the time before committing — actual offered terms can vary meaningfully once your specific financials are underwritten.

Draw Period vs. Repayment Period

Most business lines of credit are structured around two distinct phases, which is exactly what Harbor & Pine’s table above shows in miniature:

• The draw period is the window during which you can access funds, typically making interest-only payments on whatever balance is outstanding — this can last anywhere from one to several years, depending on the lender and product.
• The repayment period begins once the draw period ends (or, for many lines, simply whenever a balance is carried past a certain point), during which principal plus interest is repaid on a set schedule, similar to a term loan, and no further draws are typically allowed.

Some lines of credit are structured to revolve indefinitely, without a hard transition to a separate repayment-only phase, as long as the account stays in good standing — it’s worth confirming which structure a specific lender is offering, since the two behave quite differently over a multi-year relationship with the account.

What Businesses Typically Use a Line of Credit For

• Bridging seasonal revenue gaps, exactly like Harbor & Pine’s winter slowdown — including covering payroll tax and payroll itself during a predictable slow stretch.
• Purchasing inventory ahead of a busy season, when cash is needed before the revenue it will generate has come in.
• Managing the timing gap between invoicing and getting paid, particularly for businesses that bill on net-30 or net-60 terms but have their own bills due sooner.
• Covering an unexpected expense — an equipment repair, a sudden opportunity — without derailing cash flow management elsewhere in the business.

What it’s generally not well-suited for: a large, one-time capital purchase like real estate or a major equipment upgrade, where a term loan’s lower rate and fixed schedule are usually the better fit, and where relying on a revolving line for a purchase you have no near-term plan to repay can quietly turn convenient short-term financing into expensive long-term debt. The U.S. Small Business Administration’s own guidance on when a line of credit may be a smart choice covers several of these same use cases directly, and is a good neutral reference point alongside any specific lender’s marketing material.

If a line of credit isn’t the right fit at all — for a startup with no revenue history yet, for instance — it’s worth knowing what the alternatives actually look like before assuming debt financing is the only path forward; our guide to raising money without a loan covers several of them.

How to Qualify: What Lenders Look At

• A clear, honest picture of revenue and cash flow — often 6–24 months of bank statements or financial statements, depending on the lender.
• Business and personal credit history, particularly for a newer business.
• Time in business, with many lenders setting a minimum threshold before they’ll consider an application at all.
• A clear purpose, even though a line of credit is flexible by design — lenders still generally want to understand what it will typically be used for.
• Collateral, if applying for a secured line, with documentation supporting its value.
• A business loan agreement you’ve actually read, not just signed — the draw period length, rate structure, any minimum draw or maintenance fees, and what happens at renewal are all worth understanding before you need to rely on the line under pressure.

Common Line of Credit Mistakes

• Treating it as free money rather than real debt. A line of credit is genuinely useful precisely because it’s flexible — but every dollar drawn is a dollar that has to be repaid with interest, the same as any other form of debt financing.
• Using it as a substitute for having any cash reserve at all, rather than as a supplement to one — a business with zero cash cushion and a maxed-out line of credit has less flexibility in a real emergency, not more.
• Not reading the renewal terms. Some lines of credit require an annual review or renewal, and a lender can reduce or decline to renew a limit based on changed financials — worth knowing well before you’re depending on the line being there.
• Missing minimum draw requirements or unused-line fees. Some lenders charge a small fee on the undrawn portion of the limit, which can be a genuine drag on cost if a business secures a large line it rarely uses.
• Drawing for a purchase that doesn’t fit a revolving structure. A major equipment purchase carried on a line of credit for years, rather than repaid within a normal draw cycle, often ends up costing more than a term loan would have for the same purchase.
• Letting a creditor relationship go quiet. Communicating with your lender before a payment problem happens, not after, generally leads to a far better outcome than silence followed by a missed payment — a lender that trusts a debtor’s communication has more flexibility to work with than one that’s been surprised.

Frequently Asked Questions

What is a line of credit in simple terms? A flexible form of financing that lets a business draw funds up to an approved limit as needed, repay what’s drawn, and draw again — with interest charged only on the amount actually outstanding, not the full limit.

How is a line of credit different from a loan? A term loan delivers one lump sum upfront with interest charged on the full amount from day one. A line of credit is revolving — you draw only what you need, when you need it, and interest applies only to that drawn amount.

What’s the difference between a secured and unsecured line of credit? A secured line is backed by pledged collateral, generally allowing for a higher limit and lower rate. An unsecured line isn’t backed by a specific asset, which usually means a lower limit and higher rate, often alongside a personal guarantee.

Do I pay interest on a line of credit I haven’t used? Generally no interest on the undrawn portion, though some lenders charge a separate small maintenance or unused-line fee — worth checking in the specific agreement before assuming there’s zero cost to an unused line.

How long does a line of credit last? It varies by lender — some have a defined draw period followed by a separate repayment period, while others revolve indefinitely as long as the account remains in good standing and is periodically reviewed.

What can a business line of credit be used for? Most commonly for short-term, recurring, or seasonal needs — covering payroll during a slow stretch, purchasing inventory ahead of a busy season, or bridging the gap between invoicing and getting paid — rather than large one-time purchases better suited to a term loan.

Is a line of credit better than a business credit card? Neither is universally better — a line of credit typically offers a lower rate and sometimes direct cash access, while a credit card is often simpler to use for smaller, everyday purchases and may offer rewards a line of credit doesn’t.

What credit score do I need for a business line of credit? It varies by lender, but both personal and business credit history are typically considered, alongside revenue, cash flow, and time in business — a stronger credit profile generally unlocks better rates and higher limits rather than being a strict pass/fail cutoff.

Final Thoughts

A line of credit exists to solve a specific, common mismatch: a business’s expenses don’t always arrive on the same schedule as its revenue, and a line of credit is financing built specifically to flex with that mismatch instead of ignoring it. Harbor & Pine didn’t need $50,000 sitting in an account year-round accumulating interest charges — they needed access to roughly $15,000–$20,000 for a few months each winter, and a revolving structure that let them pay for exactly that, nothing more.

If you’re weighing whether to apply for a secured or unsecured line, the decision really comes down to understanding what you’d be pledging and what that exposure actually means — which is exactly what our companion guide to what collateral is walks through next, with real numbers on how lenders decide how much a pledged asset is worth.