Subcontractor Cash Flow — GC Concentration

WHEN ONE GC IS HALF YOUR REVENUE, THAT GC OWNS YOUR CASH.

QUICK ANSWER

GC concentration risk is what happens when one general contractor represents 50% or more of a subcontractor's annual revenue. When that GC pays slow, the subcontractor's entire cash position degrades. When that GC disputes a pay app, it can shut down the business. When that GC goes under, the subcontractor can too. Most subcontractors do not know their GC concentration because nobody is tracking it monthly. SPM surfaces it in the CEO Report so the owner can see it before it becomes a crisis.

GC relationships are not bad. Winning repeat work from the same GC is a sign of a good reputation. The problem is not the relationship — it is the financial exposure that comes with dependency on one payment source for the majority of your income.

BY JOSH LUEBKERPublished: June 2026Updated: June 2026

The Risk

What GC Concentration Actually Does to Your Business.

CASH FLOW

One Slow Month from That GC Breaks Your Cash Position

If one GC is 60% of your revenue and they run 30 days slow one month — not unusual, just slower than usual — you are short 60% of your expected cash for 30 extra days. On $5M in annual revenue that is roughly $250K in unexpected float. Most subcontractors do not have $250K sitting idle. The line of credit fills the gap, then takes months to pay back, and the cycle repeats every time that GC has a slow period.

AR AGING

A Dispute with That GC Goes Straight to 90+ Days

When a GC disputes a pay app — even a small portion of it — the whole invoice can sit in limbo. With a concentrated GC relationship, a disputed $80K invoice can represent 3–4 months of net profit sitting uncollected while the dispute works through their internal process. SPM's collections process flags this at 30 days, not 90. The early flag is what creates leverage to resolve it before it becomes a crisis.

NEGOTIATING LEVERAGE

The GC Knows They Have Leverage Over You

When a subcontractor gets 60% of their revenue from one GC, the GC is not always unaware of that dependency. Slow payments, change order disputes, and scope creep go uncontested more often when the subcontractor cannot afford to damage the relationship. The financial dependency creates a power imbalance that shows up in collections, change order approvals, and contract terms — all of which directly affect margin.

How SPM Tracks It

Concentration Surfaces in the Monthly CEO Report.

GC concentration is not a one-time calculation — it changes every month as jobs start and finish. SPM tracks revenue by GC in the CEO Report so the owner always knows what percentage of current and projected revenue comes from each source. When one GC crosses 50% of projected revenue for the next 90 days, that is a flag. Not necessarily a problem — but something to be aware of before it becomes a cash flow event.

<30%

Healthy Single-GC Concentration

One GC under 30% of revenue. Full disruption to that relationship is painful but survivable.

30–50%

Watch Zone

One GC at 30–50%. Active tracking required. Any payment slowdown creates a cash event.

>50%

High Risk

One GC over 50%. Cash position is directly tied to that GC's payment behavior. Diversification is a financial priority.

CONCENTRATION BY TRADE

HOW CONCENTRATION BUILDS, TRADE BY TRADE.

Electrical: The Pipeline GC

One GC wins the data center program and suddenly feeds 70% of your book. The work is excellent until the program ends, the GC's pricing demands tighten, or their pay cycle stretches — and every one of those moves hits 70% of your cash flow at once. Pipeline concentration feels like loyalty and prices like risk.

Civil: The Developer Dependence

Civil subs feeding one developer's subdivisions inherit that developer's lot-closing cash cycle, their lender's mood, and their market exposure. When the developer pauses a phase, the sub's revenue pauses with it — with overhead and equipment payments that don't.

Fiber & Telecom: The Carrier Master Contract

A $2.4M fiber sub's revenue ran almost entirely through major carrier work — great rates, brutal dependence. When a competitor poached the crews servicing those contracts, $6M of revenue capability vanished with them. Client concentration and capability concentration compound each other.

SWPPP & Municipal: The Agency Anchor

Multi-site trades anchored to one municipality or one master service agreement carry renewal risk on the whole book. One procurement cycle, one new administration, one rebid — and the anchor client becomes a hole the size of the company.

MANAGING IT

WHAT CONCENTRATION DISCIPLINE LOOKS LIKE.

$6M

Revenue that disappeared with one dependency. The fiber contractor's concentration story is the cautionary tale: fifteen employees left for a competitor, the carrier contracts couldn't be staffed, and $6M in revenue evaporated — discovered through the grapevine, not a report. Monthly visibility now lets him see client profitability, reward the crews that drive it, and build contracted structured-cabling work that doesn't depend on one customer.

13 Weeks

Each GC's pay behavior, modeled separately. Concentration risk lives in the cash forecast before it lives anywhere else. CFOS models each major GC's actual pay behavior — not the contract terms, the behavior — so a single GC slowing from 45 to 70 days shows up as a forecasted gap weeks before it's a missed payroll. You can't diversify yesterday, but you can see the exposure today.

<40%

The working ceiling for any single GC. The discipline target: no single GC above 40% of revenue, and bid pipeline managed toward it. Getting there isn't firing your best client — it's pricing new-GC work to win, qualifying two relationships a quarter, and letting growth dilute the concentration instead of deepening it.

FAQ

Common Questions About GC Concentration Risk.

What percentage of revenue from one GC is actually too much?

Above 50% you're effectively an unsecured division of that GC — their slow month is your crisis, and they know it at the negotiating table. The working band: keep any single GC under 40%, and treat 25–30% as the comfort zone. Context adjusts the line — a bonded public GC at 45% is safer than a thinly capitalized private one at 30% — but the math is unforgiving either way: at 60% concentration, losing the relationship doesn't shrink the company, it ends it.

How do we diversify without damaging the relationship that built us?

Quietly and additively. Diversification isn't taking work away from your anchor GC — it's pointing growth somewhere else. Keep serving the anchor at full quality, then qualify with two new GCs a quarter, price early work with them to win, and let new revenue dilute the percentage while absolute dollars with the anchor stay flat or grow. The anchor never feels a change. What changes is that their next pricing squeeze meets a sub who can afford to say no — which, paradoxically, tends to improve the relationship.

What is GC concentration risk?

GC concentration risk is the financial exposure that comes from having one general contractor represent a large percentage of a subcontractor's revenue. When that GC pays slow, disputes invoices, or experiences financial difficulty, it directly impacts the subcontractor's cash position in proportion to the concentration.

What percentage is considered high concentration?

SPM flags any single GC above 50% of projected 90-day revenue. The 30–50% range is a watch zone — active monitoring but not necessarily a crisis. Under 30% is generally manageable. Above 50% means a single payment event from that GC can create a cash crisis.

How does SPM track GC concentration?

Revenue by GC is tracked in ControlQore and surfaced in the monthly CEO Report. SPM reviews concentration percentages in the monthly accountability meeting so the owner always knows their exposure before it becomes a cash event, not after.

Should a subcontractor avoid working with one GC heavily?

Not necessarily. Repeat work from a trusted GC is a sign of a good reputation and reduces bid costs. The goal is awareness, not avoidance. When concentration is high, SPM strengthens the collections process with that GC, monitors AR aging more tightly, and ensures the cash flow forecast reflects the concentration risk explicitly.