2026 Guide: How to Estimate Borrowing Base for ABL Facility

TL;DR

A borrowing base is the lender’s formula for how much you can actually draw under an asset-based lending facility at any given time. To estimate it, start with your accounts receivable and inventory, strip out ineligible assets, apply advance rates (typically 70%–85% for AR and 35%–65% for inventory), subtract lender reserves, then compare the result to your facility limit and current borrowings. Your gross balance sheet will almost always overstate real availability, sometimes by half or more.

What Is a Borrowing Base?

A borrowing base is the maximum amount a borrower can draw under an asset-based lending facility at a specific point in time, calculated using the lender’s formula for eligible collateral, advance rates, and reserves. It is not the same as your total asset value, and it is not the same as your approved credit limit.

Think of it this way. A lender approves a $1.5 million facility. That is the ceiling. But the amount available to draw on any given day depends on what your AR and inventory look like right now, after the lender has applied its eligibility filters and haircuts. The borrowing base formula is the mechanism that governs this.

For most operating-company ABL facilities, the borrowing base starts with accounts receivable and inventory, then discounts those assets based on quality, collectability, salability, and lender control. The borrowing base changes as your AR ages, customers pay, inventory moves, and reserves adjust. It is a living number, not a one-time calculation.

If you are considering an ABL facility and want to understand what availability might look like before approaching a lender, submit a loan enquiry to start the conversation.

The Borrowing Base Formula

The simple version looks like this:

Borrowing base = (eligible receivables x AR advance rate) + (eligible inventory x inventory advance rate) , reserves

The full availability version adds one more layer:

Available to draw = lesser of (borrowing base or facility limit) , current loan balance , letters of credit , additional obligations

The word “eligible” is doing most of the work in this formula. Gross AR and gross inventory will always be higher than what the lender counts. The gap between gross assets and eligible collateral is where most borrowers miscalculate.

For a deeper look at how asset-based lending works and who qualifies in Canada, see this guide on asset-based lending in Canada.

Facility Limit vs. Borrowing Base vs. Availability

Before estimating a borrowing base for an asset-based lending facility, understand these three terms. Competitors and even some lenders blur them, which leads to confusion.

Term	What it means	Why it matters
Facility limit (commitment)	The maximum line the lender approved	The ceiling, not guaranteed availability
Borrowing base	Formula value of eligible collateral after advance rates and reserves	The live, collateral-based cap on what you can draw
Excess availability	Borrowing base minus current usage	The cushion lenders monitor closely

CAFA, a Canadian finance association, explains that a borrower can draw up to the lesser of the current borrowing base or the approved facility, and the gap between borrowings and the borrowing base is called excess availability. Minimum excess availability thresholds can trigger different loan provisions or tighter lender controls, including springing covenants that only activate when the cushion gets too thin.

A company with a $2 million facility limit and a $900,000 borrowing base can only draw $900,000 (minus what is already outstanding). The facility limit is a promise of capacity, not a promise of cash.

Step-by-Step: How to Estimate Your Borrowing Base

Step 1: Gather Current AR and Inventory Reports

Before running any numbers, collect the documents a lender will eventually want:

AR aging by customer and invoice date
Customer concentration report
Credit memo and returns history
Dispute log
Inventory listing by category and location
Most recent inventory count or cycle count
GL reconciliation for AR and inventory
Existing debt agreements and security registrations
Tax, HST/GST, and payroll remittance status

A field-exam practitioner on LinkedIn emphasized that the quality of financial information matters enormously. AR aging must reconcile to the general ledger, and eligibility must address concentrations, related-party balances, aged invoices, and inventory valuation. If your data does not reconcile, a lender will either add reserves or decline to include that collateral.

For a full list of what Canadian lenders typically request, see this working capital document checklist.

Step 2: Remove Ineligible Receivables

Start with your gross AR balance, then subtract everything a lender will not count. Common exclusions include:

Invoices aged beyond 90 days from invoice date (or 60+ days past due)
Related-party receivables
Disputed invoices and contra accounts
Foreign receivables without credit insurance or acceptable documentation
Amounts exceeding customer concentration caps (often 10%–25% of eligible AR)
Unbilled revenue or progress billings
Receivables from financially weak account debtors

Bank of America notes that current receivables in ABL typically means less than 90 days from invoice date or no more than 60 days past due. Some lenders use a “cross-aging” rule: if more than a set percentage (often 50%) of a single customer’s balance is past due, the entire balance from that customer becomes ineligible.

Step 3: Remove Ineligible Inventory

Split your inventory into categories and exclude what the lender will not advance against:

Work-in-process (WIP)
Obsolete or slow-moving goods
Perishable inventory
Customer-specific or custom-manufactured goods
Consigned or vendor-owned inventory
Inventory at unapproved locations (third-party warehouses, foreign sites)
Inventory without reliable counts or reconciliation

The OCC’s Comptroller’s Handbook states that WIP often has limited liquidation value and is frequently excluded from borrowing bases. Finished goods and commodity-like raw materials usually receive the best treatment because they can be sold more quickly at a predictable discount.

Step 4: Apply Advance Rates

Advance rates are the percentage a lender will lend against eligible collateral. They are not uniform, and they are not guaranteed. Typical benchmarks for Canadian ABL facilities:

Collateral type	Common advance rate range
Eligible accounts receivable	70%–85%
Eligible finished goods inventory	35%–65% of cost, or up to 80% of NOLV
Work-in-process	Often excluded or heavily discounted
Equipment / real estate	Varies widely, requires appraisal

CAFA cites 70%–85% for current trade receivables, while the OCC says banks typically advance up to 65% of eligible inventory book value or 80% of net orderly liquidation value (NOLV). NOLV is what a professional appraiser estimates the inventory would sell for in an orderly liquidation, net of selling costs. It is almost always lower than book value.

For more on how advance rates work and why they vary, read this explanation of advance rates in invoice finance.

Step 5: Subtract Reserves

Reserves are lender deductions that protect against identifiable risks. This is where many borrowers get surprised, because reserves can quietly reduce availability even when advance rates look generous.

Common reserves include:

Dilution reserve: protects against returns, credits, discounts, and bad-debt write-offs
Rent/landlord reserve: covers potential landlord priority claims on inventory stored at leased premises
Tax/payroll reserve: protects against CRA priority claims for unremitted HST/GST or payroll deductions
Customer concentration reserve: extra haircut when one customer represents too much of your AR
Slow-moving inventory reserve: additional discount on inventory turning slowly
Field exam / appraisal reserve: holds back fees for periodic lender inspections

The OCC notes that most ABL agreements give lenders the right to establish reserves against the borrowing base, and these reserves are deductions from collateral value that directly reduce availability.

Step 6: Compare to Facility Limit and Current Usage

The final step: take the lesser of your calculated borrowing base or the approved facility limit, then subtract what you have already drawn and any outstanding letters of credit.

Available to draw = lesser of (borrowing base, facility limit) , current loan balance , letters of credit

If the borrowing base is $875,000 but the facility limit is $1.5 million, availability is capped at $875,000 before subtracting outstandings.

Borrowing Base Example: A Canadian Distributor

This worked example shows how to estimate a borrowing base for an asset-based lending facility using realistic numbers. It is illustrative only; every lender’s formula will differ.

Assumptions:

Approved facility: $1,500,000
Current loan balance: $600,000
Letters of credit: $50,000
AR advance rate: 85%
Inventory advance: lesser of 50% of eligible cost or 80% of NOLV
Inventory NOLV (appraised): $330,000

Eligible AR Calculation

AR item	Amount
Gross AR	$1,200,000
Less: invoices over 90 days	($120,000)
Less: related-party receivables	($40,000)
Less: disputed invoices / offsets	($60,000)
Less: foreign receivables (not accepted)	($80,000)
Less: excess customer concentration	($100,000)
Eligible AR	$800,000

AR availability = $800,000 x 85% = $680,000

Eligible Inventory Calculation

Inventory item	Amount
Gross inventory at cost	$900,000
Less: work-in-process	($150,000)
Less: obsolete / slow-moving	($80,000)
Less: consigned or vendor-owned	($50,000)
Less: inventory at unapproved locations	($70,000)
Eligible inventory at cost	$550,000

Inventory advance test:

50% of eligible cost = $275,000
80% of NOLV = $264,000

Inventory availability = $264,000 (the lesser amount)

Reserves

Reserve	Amount
Dilution reserve	$24,000
Rent / landlord reserve	$15,000
HST/GST/payroll priority reserve	$20,000
Field exam / appraisal reserve	$10,000
Total reserves	$69,000

Borrowing Base

Component	Amount
AR availability	$680,000
Inventory availability	$264,000
Less: reserves	($69,000)
Borrowing base	$875,000

Available to Draw

Component	Amount
Borrowing base	$875,000
Facility limit	$1,500,000
Lesser of the two	$875,000
Less: current loan balance	($600,000)
Less: letters of credit	($50,000)
Estimated availability	$225,000

The company has $2.1 million in gross working-capital assets but only $225,000 of additional draw capacity. That gap is the result of eligibility exclusions, advance rates, reserves, and existing usage combined. This is the number that actually matters when planning cash flow.

If your estimated availability looks lower than expected, the issue may be eligibility, reserves, or deal structure, not the business itself. Get in touch to have your estimate reviewed against actual lender criteria.

What Makes Receivables Eligible?

Lenders care about whether each invoice will convert to cash on time, without disputes or offsets. The key eligibility factors:

Invoice age. Most lenders draw the line at 90 days from invoice date. Some use 60 days past due as the cutoff instead.

Dilution. This is the gap between invoiced amounts and cash actually collected, caused by returns, credits, discounts, warranty claims, and write-offs. The Journal of Accountancy gives an example where $70,000 of non-collections on $1 million of invoices equals 7% dilution. High or poorly tracked dilution leads to lower advance rates or additional reserves.

Customer concentration. If one customer represents 30% of your AR, the lender may cap that customer’s eligible balance at 15% or 20% of total receivables.

Disputes and offsets. Invoices subject to active disputes, chargebacks, or contra-account offsets are typically excluded.

Related parties. Receivables from affiliated companies, owners, or insiders are almost always ineligible.

Cross-border receivables. Foreign receivables may be excluded or discounted unless backed by credit insurance or letters of credit.

One practitioner on LinkedIn pointed out that normal management AR summaries often do not give lenders enough invoice-level detail to determine eligibility. Preparing detailed AR data, down to individual invoices, speeds up underwriting and usually produces a better borrowing base result.

What Makes Inventory Eligible?

Inventory is harder to finance than receivables because it is harder to liquidate. When lenders evaluate inventory for a borrowing base, they ask: can this be sold quickly, at a predictable discount, and does the lender control it?

Finished goods and standard raw materials get the best treatment. They are saleable, countable, and priced against a market.

Work-in-process is frequently excluded entirely. Partially assembled products have limited value to anyone other than the borrower. The OCC is explicit about this: WIP has limited liquidation value and is often left out of borrowing bases.

Obsolete and slow-moving inventory gets excluded or heavily discounted. If it has not moved in 12 months, most lenders will not count it.

Location matters. Inventory at unapproved third-party warehouses, consignment locations, or foreign facilities may not be eligible. The lender needs to be confident it can access and liquidate that inventory if necessary.

NOLV vs. book value. For inventory-heavy borrowers, the borrowing base often uses net orderly liquidation value rather than cost. A professional appraisal determines NOLV, and it is commonly 40%–70% of book value depending on the goods. If the lender caps inventory advances at 80% of NOLV, that might translate to 30%–55% of book cost in practice.

How Reserves Reduce Availability

Reserves are the least understood part of a borrowing base estimate. A lender can offer an 85% AR advance rate and still reduce your real availability by 10%–15% through reserves alone.

Reserves exist because the advance rate alone does not account for every risk. Dilution trends, landlord priority claims, unremitted taxes, customer concentration, and seasonal swings all create exposure that the lender addresses through separate deductions.

The practical lesson: when comparing ABL proposals, do not just compare advance rates. A facility with an 80% AR advance and modest reserves can deliver more availability than one with 85% and heavy reserves. Practitioners on LinkedIn warn that a larger facility can actually produce less cash if eligibility criteria are restrictive and reserves are aggressive.

For guidance on evaluating the full picture, see this guide on evaluating lender proposals.

How Often Is the Borrowing Base Recalculated?

The borrowing base is not a one-time exercise. After closing, borrowers submit a borrowing base certificate on a schedule defined in the credit agreement.

Monthly reporting is common. Weekly reporting may apply in larger or higher-risk facilities, and daily reporting is required in some cases where collateral moves quickly or the borrower’s risk profile demands closer monitoring. Bank of America notes that ABL borrowers typically provide monthly or weekly reports on borrowing-base assets.

The certificate typically includes AR aging by customer, ineligible schedules, concentration calculations, inventory reports by category, reserve calculations, current loan balances, and an officer signature.

This reporting burden is real. One alternative-lending provider estimates it can consume a meaningful share of a controller’s time. For growing companies, building the internal process early, reconciling AR aging, tracking disputes, maintaining inventory counts, and documenting reserves, makes the ongoing reporting manageable rather than a scramble.

Seven Mistakes Borrowers Make When Estimating a Borrowing Base

1. Starting with gross AR. Gross receivables almost always overstate eligible AR. Aged, disputed, concentrated, and related-party invoices will be excluded.

2. Treating inventory as a single number. Lenders split inventory into finished goods, raw materials, WIP, slow-moving, consigned, and offsite categories. Each gets different treatment.

3. Ignoring reserves. Reserves can quietly reduce availability by 5%–15% or more. They are often set after due diligence, meaning the borrower’s pre-closing estimate may be too optimistic.

4. Confusing facility limit with cash available. A $2 million commitment does not mean $2 million is always available. Availability is the lesser of borrowing base or facility limit, minus outstandings.

5. Underestimating the reporting burden. ABL is flexible but monitored. If you cannot produce clean, reconciled reports on a monthly or weekly cadence, the lender may add reserves or restrict advances.

6. Comparing offers by advance rate alone. Eligibility criteria and reserves matter just as much. A tighter eligible pool with a higher rate can produce less cash than a broader pool with a lower rate.

7. Assuming ABL ignores cash flow. ABL is collateral-driven, not collateral-only. Practitioners on Reddit emphasize that prudent ABL underwriting still considers cash flow, credit risk, and projected performance. Lenders want to see a viable business, not just a pile of assets.

Canadian Borrowers: Practical Considerations

Estimating a borrowing base for an asset-based lending facility in Canada involves a few issues that U.S.-focused resources skip.

Existing bank security. If your bank holds a general security agreement (GSA), adding an ABL lender means navigating intercreditor arrangements. The existing bank may need to subordinate on certain assets, which is not always straightforward.

PPSA registration. In common-law provinces, ABL lenders require registered security interests under the Personal Property Security Act. Ontario’s guidance states that creditors securing payment through personal property should register a financing statement under the PPSA. Quebec uses a different registration system.

Government priority claims. CRA has priority claims for unremitted HST/GST, payroll source deductions, and certain other amounts. These can rank ahead of a secured lender in liquidation, which is why ABL lenders in Canada routinely set aside reserves for these claims.

Cross-border receivables. Canadian exporters with U.S. or international customers may find that foreign receivables are excluded or discounted unless credit insurance or other protections are in place.

Market context. The Bank of Canada’s 2026 Financial Stability Report notes that Canadian SMEs rely primarily on banks and credit unions because they generally cannot issue bonds, and lending conditions are somewhat tighter for small businesses than for large borrowers. When a bank line is capped or covenant-constrained, ABL and AR finance become natural alternatives.

Size thresholds. Major-bank ABL programs (like Scotiabank’s) may target facilities of $10 million and up. Smaller borrowers can access AR finance, factoring, or specialty lending through private lenders and intermediaries. Innovation, Science and Economic Development Canada’s 2025 Credit Conditions Survey found that 45% of small businesses seeking debt financing cited working or operating capital as the intended use, confirming that this is a widespread need.

ABL vs. Factoring vs. Bank Line of Credit

If your borrowing base estimate suggests ABL might be a fit, or if the numbers are too thin, it helps to compare product alternatives.

Product	How availability works	Best fit
ABL facility	Eligible collateral x advance rates, reserves	Asset-rich companies with AR/inventory and reporting capacity
Factoring / AR finance	Invoices purchased or advanced individually	Businesses needing faster cash from invoices, lighter reporting
Traditional operating line	Bank underwriting based on cash flow and covenants	Strong balance sheet, bankable credit, lower monitoring tolerance
Equipment finance	Equipment value and repayment capacity	Machinery, vehicles, asset purchases

If your borrowing base is mostly receivables-driven and you need a simpler structure, invoice factoring may be a better starting point. If you need a general working-capital facility with fewer collateral restrictions, explore line-of-credit options.

Practitioners on Wall Street Oasis note that when the borrowing base does not cover cash-flow needs, some borrowers add a FILO (first-in, last-out) tranche. But the consensus is that it is usually better to improve borrowing-base eligibility or negotiate advance-rate terms first, since ABL is lower-cost and revolving by design.

How to Compare ABL Lender Proposals

When you have borrowing base estimates from multiple lenders, compare them on more than the headline numbers. Ask:

What assets are eligible under each lender’s formula?
What are the advance rates for AR and inventory?
What reserves are being imposed, and are they capped?
Are there customer concentration limits, and how tight are they?
How often must the borrowing base be reported?
What triggers field exams, and who pays?
What are the fees, unused line charges, and all-in cost?
Is there a minimum excess availability requirement?
Are covenants springing or ongoing?
What happens if availability falls below a threshold?

A higher facility limit with restrictive eligibility can deliver less cash than a smaller commitment with broader collateral acceptance. Practitioners on LinkedIn and Reddit consistently make this point. The offer that looks biggest on paper is not always the one that puts the most cash in your account.

Quick Borrowing Base Estimation Checklist

Before you estimate your borrowing base, gather:

Latest AR aging by customer and invoice
List of invoices past 60 and 90 days
Customer concentration breakdown
Related-party receivable balances
Active dispute and credit memo log
Returns, rebates, and allowance history
Inventory listing by category (finished goods, raw materials, WIP) and location
Consigned, slow-moving, and obsolete inventory schedules
Most recent physical inventory count or cycle count
Current financial statements and interim trial balance
Existing loan balances and security agreements
PPSA / lien search results
CRA compliance status for HST/GST and payroll
Insurance certificates and warehouse/landlord agreements

With this information in hand, you can run through the five-step estimation process above and arrive at a realistic borrowing base figure before ever speaking to a lender.

When Your Estimate Suggests ABL Is Worth Exploring

Good signs that ABL may fit:

Significant B2B receivables from creditworthy customers
Clean AR aging with manageable dilution
Saleable finished goods or commodity raw materials
Reliable inventory reporting and counts
Seasonal or growth-driven working-capital needs
Bank line not keeping pace with sales growth
Strong collateral but uneven profitability

Poor fit signals:

Mostly consumer receivables or cash sales
High disputes, returns, or untracked dilution
Specialized, perishable, or obsolete inventory
No reconciliation between AR aging and general ledger
Existing senior lender unwilling to share collateral priority
Inability to handle monthly or weekly reporting

If the borrowing base math works but your current lender cannot accommodate the structure, or if you need to combine ABL with factoring, equipment finance, or other facilities, McMillan Capital Partners helps Canadian businesses compare options and approach the right lenders.

Start a conversation with McMillan Capital Partners

Frequently Asked Questions

Is the borrowing base the same as my loan amount?

No. The loan commitment is the approved maximum facility. The borrowing base is the collateral-based amount available under the lender’s formula at a specific point in time. If your eligible collateral declines, your borrowing base shrinks, even if the facility limit has not changed.

What is a typical advance rate for accounts receivable?

Canadian advisory sources and U.S. bank examination materials commonly cite AR advance rates around 70%–85% of eligible receivables. The actual rate depends on customer quality, dilution history, concentration, industry, and reporting quality.

Why did my lender exclude some of my receivables?

Common reasons include invoice age (past 90 days), active disputes, related-party status, customer concentration exceeding caps, foreign collection risk, and contra-account offsets. Every lender defines eligibility slightly differently in the credit agreement.

Can inventory be included in a borrowing base?

Yes, but inventory receives more conservative treatment than receivables. Finished goods and marketable raw materials are usually eligible. WIP, obsolete goods, perishable items, and consigned inventory are frequently excluded or heavily discounted.

What happens if my loan balance exceeds the borrowing base?

This is called a borrowing base deficiency or overadvance. Depending on the agreement, the lender may require immediate repayment of the excess, restrict further advances, add reserves, increase monitoring, or treat it as an event of default.

How often do I need to submit a borrowing base certificate?

Monthly is most common. Larger or higher-risk facilities may require weekly reporting. In some cases, daily reporting is required. The schedule is defined in the credit agreement and can change if availability drops below certain thresholds.

Is asset-based lending only for distressed companies?

No. ABL was historically viewed as a last-resort product, but it has become mainstream. CAFA notes that ABL is used by both healthy and distressed businesses, and Bank of America frames it as a tool for asset-rich companies with significant capital needs or variable cash flows. Manufacturers, distributors, wholesalers, and retailers are all common ABL borrowers.

How is ABL different from factoring?

In ABL, the borrower retains ownership of receivables and draws against a revolving facility governed by the borrowing base formula. In factoring, invoices are purchased (or advanced against) individually, often with the factor taking on collection responsibility. Factoring can be simpler to set up and may suit businesses that need faster cash or lighter reporting, while ABL typically supports larger, more complex working-capital needs.