Your Vendor Spend Is More Concentrated Than You Think

The Risk Hiding in Your AP

Ask a contractor how many vendors they use and you'll often get a round guess. Pull the actual data and the number can be much higher. But here's the catch: the vendor count matters less than how that spend is distributed.

In Level's contractor dataset (the founding team's analysis of 2,200+ contractors that anchors the Level Index), a common pattern is a long tail of vendors and a short list of suppliers that receive most of the spend. The earlier first-party pull reported over $4 billion in accounts payable. That total, its period and the number of companies with usable AP-by-vendor data have not been re-verified for this page. Treat the vendor figures below as directional, not a published benchmark. That concentration creates risk most contractors never think about.

What the Data Shows

Four individual review patterns show why a vendor count alone is misleading. These were large outliers, not typical contractors. The company figures stay qualitative, and the periods and active-vendor definitions have not been re-verified for this page:

Average spend per vendor measures scale, not concentration. Define it from eligible vendor-bill dollars for one period divided by the vendors with those bills; do not substitute the whole vendor master or mix a closing AP balance with annual spend. A high or low average can coexist with most dollars going to a few suppliers. The fictional HHI example below makes that distinction reproducible without publishing a customer row.

To measure concentration, use top-1, top-5 and top-10 share, or a Herfindahl-Hirschman Index (HHI): square each vendor's percent share and add them up. Fictional counterexample: two contractors each spend $1M across 10 vendors, so both average $100K per vendor. Contractor A splits spend evenly at 10% each, so HHI = 10 × 10² = 1,000 and top-1 share is 10%. Contractor B sends 55% to one supplier and 5% to each of the other nine, so HHI = 55² + 9 × 5² = 3,025 + 225 = 3,250 and top-1 share is 55%. The averages are the same, but the exposure is very different when that one supplier raises prices or delays a shipment.

Reference Concentration Ranges (earlier pull)

The figures below come from the same dataset pull. The company count, the definition of an active vendor and whether 60 vendors is a mean or median have not been re-verified. The earlier first-party pull reported them as P25, median and P75; they have not been re-verified for this page. Use them as directional historical reference points for comparing your own top-5 share, with the sample and window limitations below. The earlier pull stated about 60 active vendors without a reproduced central-statistic definition, far fewer than the outlier companies above, and spend was steeply skewed:

At the middle reference, a contractor sends about a third of spend to a single vendor and three-quarters to its top 5. With 60 active vendors, the top 5 are about 8% of the vendor list, so at that reference roughly 8% of vendors receive 75% of spend. That's not just a supply chain, it's a dependency to plan for.

In individual reviews I have seen a dominant supplier receive most of a contractor's spend. That alone does not prove bad management or a dealer relationship; check the actual product mix, exclusivity terms and substitutes. Where a manufacturer relationship is deliberate, plan for changes to its pricing and dealer program rather than treating vendor diversification as an automatic fix.

The Three Types of Vendor Concentration Risk

1. Single-Source Equipment Dependency

HVAC contractors selling Trane, Carrier, or York equipment can have most of their equipment spend with a single manufacturer; check your own share. That's fine when the relationship works. It becomes a crisis when:

• The manufacturer raises prices mid-season and you've already quoted jobs at old pricing
• Lead times stretch from 2 weeks to 12 weeks (we all remember 2021-2022)
• The manufacturer changes their dealer program and you lose preferred pricing

In product catalog data from the same dataset pull (not re-verified for this page), average catalog prices were $1,498 per product for Trane, $1,370 for Carrier and $1,242 for York. Fictional example: a 10% increase on $2M of annual equipment purchases is $200K of added cost. How much of that hits margin depends on timing. On fixed-price jobs already quoted it lands in full, while on jobs not yet quoted you can price it in. If $600K of the $2M is on signed fixed-price work, the unrecoverable hit is $60K unless your contracts include escalation clauses.

2. Subcontractor Over-Reliance

Contractors that outsource heavily, and some individual reviews have shown networks of thousands of subcontractor vendors, face a different concentration risk. If your top 3 subcontractors handle 60% of your outsourced work, you're one labor shortage away from missing deadlines.

The earlier pull includes national maintenance companies managing subcontractor networks across geographies (counts not re-verified). Thousands of subcontractor vendors show network breadth, not spend concentration or realized profitability. Use each supplier's spend share and your own realized job margin to evaluate the exposure. Quoted subcontractor line items carry the thinnest margin of any cost type in the Level Index, 23.6% across 2.2M+ quote line items, so there's little room for surprises. That is quoted margin, not realized job margin.

3. Supply House Dependency

Most contractors buy materials from 2-3 local supply houses. The pricing is negotiated, the account terms are established, and the parts runner knows where everything is. That convenience creates lock-in.

When your primary supply house knows they're your only source, pricing leverage shifts to them. A 3-5% annual price increase that "matches market conditions" adds up fast on $500K+ in annual materials spend.

How to Quantify Your Risk

Here's a quick exercise:

1. Pull your AP by vendor for the last 12 months. Sort by total spend, highest to lowest.
2. Calculate concentration. What percentage of total spend goes to your top 5 vendors? Your top 10?
3. Flag single-source dependencies. Are there any vendors where you have no alternative? What would happen if they raised prices 15% tomorrow?

The tiers below are judgment-based share thresholds, not observed risk probabilities. A small share can still be critical if the supplier has no substitute, while a large share can be manageable when replacement is immediate. They conflict with the reference figures above on purpose. The unverified 75.1% middle reference would land in Concentrated, and even the 58.4% lower reference sits near the top of Moderate. Concentration is common, so contingency planning is a normal requirement, not a sign of bad management. Pair the tier with a replacement check: for each top-5 vendor, how many weeks would it take to qualify an alternative at comparable price?

The Margin Impact

Vendor concentration doesn't just create supply risk, it affects your margins directly.

From the Level Index quote-line analysis (gross margin on quoted work across 2.2M+ quote line items, cross-trade, quoted rather than realized):

If your business is heavy on equipment and subcontractor pass-through, more of your cost is set by vendor pricing. In labor-heavy service work, the biggest cost (technician time) is internal and more controllable, which is consistent with labor carrying the highest quoted margin above. This page has not re-verified a company-level comparison showing which business mix earns the highest margins.

A service-heavy model may reduce equipment-supplier exposure; that is an operating hypothesis to test, not a measured profile of the most profitable contractors: less of the cost base is vendor-priced, though wages, utilization and pricing still decide the margin.

What Smart Contractors Do

Dual-source critical materials. Don't buy all your copper, refrigerant, or ductwork from one supplier. Even if your primary supplier is 5% cheaper, having a secondary source means you have leverage when they raise prices and a backup when they can't deliver.

Negotiate annually, not reactively. A practical cadence is to renegotiate supply house terms every year. Volume commitments in exchange for price locks. Extended payment terms (Net 45 instead of Net 30) to improve cash flow. Early-pay discounts (2/10 Net 30) when cash position allows, though taking early-pay discounts only makes sense if your DSO and AR position are healthy enough to support faster outflows. The arithmetic: under 2/10 Net 30 you pay 20 days early and save 2%. On a $50,000 invoice that is $1,000, roughly a 37% annualized return (2/98 × 365/20). That usually beats leaving cash idle, but not if paying early creates a cash shortfall.

Track material cost as a percentage of revenue. If your materials-to-revenue ratio is creeping up quarter over quarter, test supplier pricing, quantity, job mix, customer prices, cutoff and estimating. The ratio alone does not isolate one cause. This is the kind of trend a fractional CFO catches in a monthly financial review.

Build subcontractor depth. For every critical trade you outsource, have at least 3 qualified subs on your approved vendor list. Price-check subs annually. A workable structure for companies with thousands of subcontractor vendors is a small core group, for example 10-15 actively managed subs, plus a bench for overflow. This is a planning pattern, not a measured count.

When Concentration Is Actually Fine

Equipment dealer relationships are inherently concentrated. If you're a Carrier dealer, you sell Carrier. That's the business model. The risk isn't the manufacturer relationship, it's failing to adjust pricing when the manufacturer adjusts theirs. Build escalation clauses into project quotes that cover manufacturer price changes.

Specialized subcontractors may be the only option in your market. If there's one controls contractor in your metro area, you're single-sourced by market reality, not by choice. In that case, the fix is a strong contractual relationship with pricing protection, not diversification.

At smaller scale, for example under $3M in revenue, a formal vendor management program may not be worth the overhead if you have a few dozen vendors you know personally. These are judgment thresholds, not measured cutoffs. Even then, run the top-5 share check once a year. The framework becomes essential when the vendor count exceeds what one person can track by memory.

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The Bottom Line

Most contractors think about sales, margins, and cash flow. Few think about the supply chain that feeds all three. When your top 5 vendors control 60%+ of your spend, a single pricing change or supply disruption can wipe out a quarter's profit. Combine that with slow invoicing speed and a weak collection rate, and you've got a cash flow crisis in the making.

And concentration risk isn't limited to the supply side, customer revenue concentration is a related exposure, with the median contractor in the Level Index getting 31.0% of revenue from its largest single customer (n=959 companies with at least $100K in annual revenue). The fix isn't eliminating concentration, it's knowing where it exists, having alternatives ready, and negotiating from a position of information. Pull your AP data, run the numbers, and know your exposure.

Q: How does Level help with vendor analysis? A: In the free audit, we review your AP-by-vendor data (for example a QuickBooks vendor spend export) and walk through concentration ratios, spend trends by vendor and margin impact. We also flag single-source dependencies and material cost inflation against revenue growth. Ask what ongoing reporting is included for your accounting setup. The first audit is free.

Q: Should I consolidate or diversify vendors? A: It depends on your leverage. If consolidating spend with one supplier gets you 10% better pricing, the savings may outweigh the concentration risk, as long as you have a backup qualified and ready. Diversify for resilience; consolidate for savings. The best contractors do both strategically.