CONCENTRATION RISK

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 percent 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 don't 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.

Most owners think of a big GC as their best customer, and for a while it is. The trouble is that one customer at 60 percent of revenue also controls 60 percent of your cash timing, your AR aging, and your negotiating position. You can't walk away from a slow payment or a disputed pay app when that relationship is most of the book. Nobody tracks the percentage, so the exposure builds over three or four good years and only becomes visible the month the GC changes how it pays. Counting it every month is what keeps it from becoming a surprise.

BY JOSH LUEBKERPublished 2026-08-06Updated 2026-10-19
THE DEFINITION

WHAT IT MEANS.

GC concentration risk is the financial exposure that comes from having one general contractor represent a large percentage of a subcontractor's revenue.

Concentration isn't a one time calculation. It moves every month as jobs start and finish, so a sub who was at 35 percent in March can be at 58 percent by August without doing anything differently. Under 30 percent of revenue from a single GC is healthy: full disruption to that relationship is painful but survivable. Between 30 and 50 percent is the watch zone, where any payment slowdown creates a cash event. Above 50 percent, the cash position is tied directly to one company's payment behavior.

Concentration builds differently by trade. An electrical sub gets pulled in when one GC wins the data center program and suddenly supplies 70 percent of the book. Civil subs supplying one developer's subdivisions inherit that developer's lot closing cash cycle. Fiber and telecom subs bring in their revenue through a carrier master contract. SWPPP and municipal subs anchored to one agency or one master service agreement face renewal risk instead of payment risk. The trade changes the mechanism, and it doesn't change the math.

WHAT CONCENTRATION DOES TO YOUR BUSINESS

WHERE THE EXPOSURE SHOWS.

01

One slow month from that GC breaks your cash position

If one GC is 60 percent of your revenue and they pay 30 days slow one month, not unusual, just slower than usual, you're short 60 percent of your expected cash for 30 extra days. On $5M in annual revenue that's roughly $250K in unexpected float. Payroll doesn't slow down to match, so the line of credit becomes the plan for a month nobody had budgeted.

02

A dispute with that GC goes straight to 90 plus days

When a GC disputes a pay app, even a small portion of it, the whole invoice can stay in limbo. A disputed $80K invoice can represent three to four months of net profit for a sub in this revenue range. The work was already done and the cost was already paid out in wages and material, so the dispute is a cash problem with a payroll deadline attached.

03

The GC knows they have leverage over you

When a subcontractor gets 60 percent of their revenue from one GC, the GC isn't always unaware of that dependency. It affects change order pricing, it affects how hard you push on a slow payment, and it affects whether you can hold your terms on the next contract. You aren't negotiating as a vendor at that point. You're negotiating as an unsecured division of their company.

THE MATH

WHAT IT LOOKS LIKE IN DOLLARS.

The float on one slow month

A GC at 60 percent of revenue pays 30 days slow on a $5M book. That's roughly $250K in unexpected float for a single month. None of it was budgeted, and payroll still goes out on Friday.

What one dispute costs

A disputed $80K invoice can represent three to four months of net profit for a subcontractor in this size range. The dispute doesn't have to cover the full amount to hold the full invoice. That's why concentration and AR aging are the same conversation.

The revenue that disappeared with one dependency

A verified fiber client did $2.4M with revenue coming almost entirely from major carrier work. Fifteen employees left for a competitor, the carrier contracts couldn't be staffed, and $6M of revenue capability vanished. The concentration didn't cause the departure, and it's the reason one staffing event took the whole book with it.

HOW SPM FIXES IT

WHAT CONCENTRATION DISCIPLINE LOOKS LIKE.

Revenue by GC, tracked monthly in the CEO Report

Revenue by GC is tracked in ControlQore and surfaced in the monthly CEO Report, so the percentage is a number the owner reads every month instead of something somebody remembers to check. SPM flags any single GC above 50 percent of projected 90 day revenue. The 30 to 50 percent band gets watched, and under 30 percent is generally manageable.

Each GC's pay behavior, modeled separately in the 13 week forecast

Concentration risk lives in the cash forecast before it lives anywhere else. The 13 week cash forecast models each GC's payment behavior on its own rather than blending everybody into one average, because the average is what keeps the exposure out of view. A GC that pays at 45 days gets forecast at 45 days.

A working ceiling of 40 percent, with the bid pipeline pointed at it

The discipline target is no single GC above 40 percent of revenue, with the bid pipeline managed toward that ceiling. Diversification is pointing growth somewhere else. Qualify with two new GCs a quarter, price the early work to win it, and let new revenue dilute the percentage while the anchor GC's dollars stay flat or grow.

Collections that flag at 30 days instead of 60

High concentration requires stronger collections than a diversified book does, because there's less room to absorb one slow payment. Every invoice gets flagged at 30 days and worked from there. AR aging is monitored by GC separately, so a slowdown at the anchor GC is visible in week five and not at quarter end.

WHAT YOU GET

THE OUTPUTS, NAMED.

Monthly CEO Report with revenue tracked by GC
Monthly accountability meeting that reviews the concentration percentages
13 week cash flow forecast modeling each GC's payment behavior separately
Collections process that flags every invoice at 30 days
$10.7M+
Client AR Recovered Since 2023
48
Active Trade Specializations
60 DAYS
Average Onboarding Time
PRICING

FLAT MONTHLY FEE. NO SURPRISES.

Three tiers, priced by your trailing twelve month revenue. Which one you're in depends on how much of the work you want off your desk. No hourly billing. No payroll. The one-time onboarding fee is right here in the table.

Last 12 months revenueMonthly feeOne-time onboarding
Under $1M$1,900 to $3,300$1,000
$1M to $3.5M$2,600 to $5,300$1,500
$3.5M to $6.5M$3,800 to $8,300$3,000
$6.5M to $9.5M$5,100 to $11,800$4,500
$9.5M to $12.5M$6,100 to $14,900$6,000
$12.5M to $15.5M$7,400 to $17,650$7,500
$15.5M to $18.5M$9,400 to $22,400$9,000
$18.5M+Quoted individuallyQuoted individually

The onboarding fee covers migrating your books back to the start of your last taxable year and getting you fully operational in 60 days. It's billed once, with your first invoice. It's the same for all three tiers. Your first month is prorated, and your monthly engagement starts on the first of the first full month.

Range reflects the three tiers below. Which one you're in depends on how much of the work you want off your desk. No payroll. No hidden line items. The onboarding fee is right here in the table.

Core

You stop guessing.

You get the CFO work. Job costing built against the way you estimate, a 13 week cash forecast, monthly WIP, and a meeting every month that ends in decisions and never in a report.

Your bookkeeper still does the books.

Strategic

Every job shows its margin while it is still open.

Everything in Core, plus the bookkeeping and bank reconciliations done for you, and the job costing and WIP software set up, loaded with your cost codes, and managed every month. Use your own online software, or move to ours and we cover it.

A bookkeeper we choose does the books and reconciliations. No payroll.

Platinum

You approve, and the money side gets handled.

Everything in Strategic, plus a controller we choose who handles your bills and receivables for you the way an in-house controller would. They call vendors, pay the bills and keep the accounting current. We plan the cash flow first, and you approve every payment because it is your money.

A controller we choose does the payables and receivables. No payroll, no pay applications, no collections.

COMMON QUESTIONS

FREQUENTLY ASKED.

Above 50 percent you're effectively an unsecured division of that GC, and their slow month is your crisis. Keep any single GC under 40 percent, with 25 to 30 percent as the comfort zone. Context moves the line, because a bonded public GC at 45 percent is safer than a thinly capitalized private one at 30 percent.

Do it additively, and without announcing it. Diversification is pointing growth somewhere else. Qualify with two new GCs every quarter, price the early work to win, and let the new revenue dilute the percentage while the anchor GC's dollars stay flat or grow.

SPM flags any single GC above 50 percent of projected 90 day revenue. The 30 to 50 percent band is the watch zone. Under 30 percent is generally manageable, because above 50 percent a single payment event can create a cash crisis on its own.

Revenue by GC is tracked in ControlQore and surfaced in the monthly CEO Report. The percentage is reviewed in the monthly accountability meeting alongside AR aging by GC. The number stays in front of the owner every month rather than getting calculated once during a bad quarter.

Not necessarily. Repeat work from a trusted GC is a sign of a good reputation, and the goal is awareness rather than avoidance. High concentration just requires stronger collections, tighter AR aging monitoring, and explicit cash flow forecasting than a diversified book does.
WHAT THIS TIES INTO
Josh Luebker, SPM The Construction CFO
Josh Luebker
FRACTIONAL CFO · SPM THE CONSTRUCTION CFO

Josh Luebker is a master electrician turned construction CFO, president of SPM The Construction CFO and author of CONTROL: C.F.O.S. Construction Financial Operating System.

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