You apply for an asset-based loan and the lender comes back with a number. Maybe it’s higher than you expected. Maybe it’s lower.
Either way, that figure didn’t come out of nowhere. It came from a borrowing base.
Understanding what is borrowing base in asset-based lending matters because it directly controls how much you can borrow at any given time. The number isn’t fixed when your loan closes. It moves as your receivables, inventory, and other collateral shift in value.
That means your actual access to capital can change month to month.
This guide breaks down how borrowing bases work, what counts as eligible collateral, and how lenders calculate the maximum loan amount they’ll extend.
What Is a Borrowing Base?
A borrowing base is the maximum amount a lender will advance against the assets you’ve pledged as collateral.
Think of it as a moving credit limit inside a larger credit facility. The total facility size might be $2 million, but the borrowing base determines how much of that you can actually draw on at any given moment.
Lenders typically assess short-term, liquid assets on your balance sheet when determining a borrowing base. That usually means accounts receivable and company’s inventory, though equipment and other assets sometimes factor in.
The borrowing base is updated periodically, such as monthly or quarterly, to protect the lender’s downside risk. Some facilities update weekly, especially for larger or more volatile businesses.
Here’s why this matters for your business:
- Your borrowing capacity rises and falls with your collateral position
- A strong month of sales can expand your access to capital
- A bad month, or a customer who stops paying, can shrink it
The borrowing base effectively acts as a credit limit that flexes with your business performance, which is what makes asset-based lending different from a fixed-amount term loan.
How Asset-Based Lending Uses the Borrowing Base
Asset-based lending is a financing structure where your loan is secured by specific business assets rather than a fixed credit profile or cash flow projection.
The amount you can borrow flexes with the value of those assets. The borrowing base is what makes that flexibility work.
Lenders rely on borrowing bases to mitigate credit risk by ensuring loans are secured against specific assets, which can be adjusted based on the collateral’s value. That structure benefits both sides. The lender has ongoing visibility into the assets backing the loan, and you get access to more working capital as your business grows.
Common asset classes used as collateral in asset-backed lending include:
- Accounts receivable (typically the largest component)
- Company’s inventory (finished goods, sometimes raw materials)
- Equipment and machinery
- Real estate (in larger facilities)
- Intellectual property (less common, more complex to value)
For most businesses, using an asset-backed loan, receivables and inventory do the heavy lifting. These are the assets lenders prefer because they can be converted to cash relatively quickly if the loan goes into default.
The trade-off is that asset-based lending requires more ongoing reporting than a standard loan. You’re effectively giving the lender a live view of your collateral position, which is the basis for how much debt capital they’ll extend at any given time.
What Counts as Eligible Collateral
Not every dollar of receivables or inventory on your balance sheet counts toward your borrowing base. Lenders apply eligibility rules to filter out assets they consider too risky or too hard to convert to cash.
Here’s how the main categories typically break down:
Accounts Receivable
Accounts receivable usually carry the highest advance rate in a borrowing base because they’re the most liquid form of business collateral. But only your company’s eligible receivables count toward the calculation.
Standard eligibility criteria include:
- Invoice has been issued for goods delivered or services completed
- Customers are based domestically (foreign receivables often excluded or capped)
- Invoice is within the aging window, typically under 90 days
- No single customer represents too large a share of total AR (concentration risk)
- Customer has no pending dispute or offset against the invoice
Aging matters most. Once a receivable crosses the 90-day mark, most lenders treat it as ineligible, regardless of how likely you are to collect. That’s why AR quality directly affects your borrowing capacity. Strong collection practices keep more of your receivables inside the eligible pool.
Inventory
Your company’s inventory is harder to value and harder to liquidate, which is why it gets a lower advance rate. Inventory generally has lower advance rates, ranging from 50% to 60% of its value, due to liquidation difficulties.
Lenders look at:
- Inventory type (finished goods preferred over work-in-progress or raw materials)
- Turnover speed (slow-moving stock often excluded)
- Obsolescence (out-of-date items written off)
- Location and storage conditions (warehoused inventory easier to verify)
If your inventory sits on shelves for months, expect the eligible portion to shrink.
Other Collateral
Equipment, real estate, and occasionally intellectual property can also feed into a borrowing base, though usually under separate advance rate schedules. Accounts payable can work against you in the calculation. If you owe suppliers with liens against specific inventory, that portion may be carved out of your eligible collateral.
How the Borrowing Base Is Calculated
The borrowing base calculation follows a consistent logic, even though the specific inputs vary by lender. The calculation of the borrowing base is contingent on the specific terms laid out in the lender agreement between the lender and borrower, and it typically involves summing the value of eligible collateral and applying a discount factor.
The process generally works in four steps:
- Identify eligible collateral. Strip out anything that fails the lender’s eligibility tests (aged receivables, obsolete inventory, concentration issues).
- Apply the advance rate to each asset class. Receivables might get 80% to 90%. Inventory might get 50% to 60%. Equipment varies.
- Subtract reserves and ineligibles. Lenders often hold back a reserve for disputes, returns, or other risks.
- Sum the components to produce the total borrowing base.
The formula, in its simplest form, looks like this: the sum of the collateral pledged by the borrower, adjusted downward by the advance rate, which varies based on the collateral’s quality and liquidity.
Lenders often apply a discount factor to the value of collateral, known as margining, to mitigate risks and establish a reliable credit limit for businesses. The discount is what protects the lender if collateral values drop or if liquidation recovers less than book value.
One thing to keep in mind: lender policies cause real variation here. Two lenders looking at the same business can produce different borrowing bases based on their internal risk tolerances, industry experience, and reserve practices. That’s why comparing offers from multiple lenders often reveals meaningful differences in available maximum loan amount.
Borrowing Base Calculation Example
Here’s a simplified example to show how the numbers come together.
A wholesale distributor has the following on its balance sheet:
- $600,000 in accounts receivable, of which $500,000 is eligible (the rest is over 90 days or concentrated with a single customer)
- $400,000 in inventory, of which $300,000 is eligible (the rest is slow-moving or obsolete)
Their lender applies an 85% advance rate on receivables and a 55% advance rate on inventory.
| Asset | Eligible Value | Advance Rate | Available Borrowing |
| Accounts receivable | $500,000 | 85% | $425,000 |
| Inventory | $300,000 | 55% | $165,000 |
| Total borrowing base | $590,000 |
So even though the business has $1 million in receivables and inventory on its books, the total borrowing base lands at $590,000. That’s the maximum the distributor can draw against the facility at this point in time.
Run the math next month with different inputs, and the number changes. That fluctuation is the defining feature of a borrowing-base-driven facility.
Advance Rates and What Drives Them
The advance rate is the percentage of an asset’s value that a lender will count toward your borrowing base. It’s the single biggest variable in the calculation, and small differences add up quickly.
Typical ranges look like this:
- Accounts receivable: 80% to 90%
- Inventory: 50% to 60% (often lower for raw materials or work-in-progress)
- Equipment: 50% to 75%, depending on type and resale market
- Real estate: 65% to 80% of appraised value
What pushes your advance rate up or down:
- Concentration risk: heavy reliance on one or two customers usually drags the AR advance rate lower
- AR aging trends: consistently slow collections signal higher risk
- Industry: lenders apply tighter rates in volatile or seasonal industries
- Inventory turnover: faster turnover supports higher rates
- Liquidity of the underlying asset: harder-to-sell assets get lower rates
Advance rates are negotiable in some cases, especially as your business builds a track record with the lender. Demonstrating clean reporting, predictable collections, and low dispute rates over time can support a case for better terms at renewal.
That said, advance rates aren’t infinitely flexible. They reflect how the lender has priced the risk of the underlying collateral, and there’s only so much room to move without changing the structure of the facility itself.
The Borrowing Base Certificate
A borrowing base certificate is a formal document that outlines the relevant terms and provisions regarding the collateral, including the method for recalculating the borrowing base as collateral values fluctuate. It plays a different role at two stages of the lending relationship.
- During the loan application process, you don’t submit a formal certificate yet. Instead, the lender uses your AR aging reports, inventory schedules, and financial statements to model what your borrowing base would look like if the facility were live.
This estimate drives the proposed facility size and advance rates in the term sheet. Many businesses are surprised at this stage to see how much of their receivables and inventory are stripped out as ineligible. - After closing, the certificate becomes a recurring deliverable. You submit it to your lender on a set schedule to confirm your current borrowing position before drawing additional funds.
Standard data fields on the certificate include:
- AR aging schedule
- Inventory report (by category and location)
- List of ineligibles and reserves
- Calculation summary showing the total borrowing base
- Authorized signature from a designated officer
Submission frequency depends on the facility. Monthly is standard for most asset-based loans. Weekly or even daily submissions are common for larger facilities or businesses with volatile collateral positions.
Regular updates to the borrowing base certificate are necessary to reflect changes in a company’s total collateral status, which helps maintain access to debt capital. Missing a submission or submitting inaccurate data can trigger a freeze on new draws until the issue is resolved, which is why accurate reporting matters more than most borrowers realize at the outset.
How to Improve Your Borrowing Capacity
Your borrowing base isn’t fixed. The decisions you make around AR, inventory, and reporting directly affect how much capital you can access month to month. The most common issues that shrink borrowing capacity are also the most fixable.
Here’s where to focus:
- Tighten AR collection cycles. Receivables that slip past the 90-day aging window get stripped from your eligible pool. Faster collections keep more of your AR working for you.
- Diversify your customer base. Concentration risk is one of the biggest reasons lenders write down receivables. If a single customer represents more than 15% to 20% of your AR, expect the lender to cap or exclude the excess.
- Clean up inventory records. Obsolete or slow-moving stock often gets carved out of the borrowing base. Regular write-offs and clear turnover data help preserve eligible inventory value.
- Resolve disputed invoices quickly. Any invoice with a pending dispute or offset typically becomes ineligible until cleared.
- Close documentation gaps. Missing backup invoices, unsigned shipping confirmations, or unreconciled subledgers all give lenders reason to reduce your borrowing base. Accurate reporting prevents most of these issues before they happen.
- Automate where possible. Manual borrowing base calculations on spreadsheets create errors and lag. Integrating your AR aging and inventory systems lets you see your borrowing position in real time.
- Communicate proactively with your lender. If you see a covenant trend heading the wrong way, raising it early gives you more room to manage the situation than waiting for the lender to flag it.
Most of these come down to operational discipline. Businesses that treat borrowing base management as an ongoing process, not just a monthly reporting task, consistently maintain better access to working capital and stronger relationships with their lenders.
Finding the Right Financing Fit
Understanding how a borrowing base works gives you a clearer picture of what asset-based lending can do for your business.
But ABL isn’t the only path, and it isn’t always the best one.
A business with strong receivables and steady inventory turnover may get more flexibility from an asset-based facility. Another business with predictable cash flow but lighter collateral may be better served by a term loan or line of credit.
At SMB Compass, we work with business owners to compare financing options across our network of funding partners. That way, you can see how an asset-based structure stacks up against other paths before committing.
If you’re weighing asset-based lending or exploring other small business loan programs, we’re happy to walk you through your options.
