You're an Interest-Free Loan to the GC: Subcontractor Cash Flow Survival

The single sharpest summary of subcontractor economics I've read came from a r/Construction post:

"Everyone has cash flow issues. Being a sub, you're an interest-free loan to the GC with little leverage to get paid quickly."

That's the whole game. Subs fund the GC's working capital. Under a delayed-payment arrangement, the sub can carry the funding gap for 60-90 days, including periods when the GC is itself waiting on the owner. Actual contract terms and payment history determine the financing exposure.

This post is about why that's structural, what leverage you actually have, and how the smartest subs play the game.

Why the GC system was designed this way

It's not personal. The general contractor system is built so that:

1. The owner pays the GC monthly based on percent complete
2. The GC marks up sub costs 5-15% (their margin)
3. The GC waits to pay subs until after they receive the owner's payment
4. The GC holds retainage from subs until project completion
5. The GC's working capital cost is effectively zero

You finance steps 3 and 4. The GC charges interest in the form of markup. You don't see your share.

The math: a 60-day delay in payment at a 12% cost of capital is roughly 2% of the contract value. On a $500K project, that's $10,000 of financing cost you're absorbing. If every dollar of an assumed$3M annual revenue is paid 60 days after work, a 12% annual cost of capital implies about$60K of annual financing cost to the sub. This is a sensitivity, not a measured client cost or cash transferred directly to the GC.

The "leverage" you actually have

Subcontractors have less leverage than they think, but more than they use. The actual tools:

1. Prompt pay statutes (state-specific, real teeth)

Prompt-pay statutes can set payment deadlines after specified events. The following are rough planning ranges, not statutory deadlines for a particular claim:

• 7-15 days from GC receipt of owner payment (private projects)
• 5-10 days (public projects, often with statutory interest if violated)

California, Texas, Florida, New York, Pennsylvania, Illinois and Washington have different rules. Verify the current statute for the state and public/private project, the payment trigger, contractual exceptions, disputed amounts and any pay-if-paid clause with counsel.

The next step is a supported written demand citing the applicable contract and statute. A demand is not proof of collection or a substitute for preserving claim deadlines.

2. Mechanics lien rights (powerful, time-sensitive)

A mechanics lien attaches to the property for unpaid work or materials. It clouds the title and prevents resale or refinancing until satisfied.

Critical timing rules vary by state:

• California: Covered subcontractors and suppliers generally serve a preliminary 20-day notice. The usual 90-day recording window after completion can shorten to 30 days for subcontractors/suppliers after a recorded notice of completion or cessation. Check applicable service and completion rules in CSLB guidance.
• Texas: For unpaid labor or materials, derivative-claimant notices generally go to the owner and original contractor by the 15th of the third month after the work month (nonresidential), or the second month (residential). Lien-affidavit deadlines for non-original contractors generally run to the 15th of the fourth month after the last-work month (nonresidential), or the third month (residential). Retainage has a separate third-month deadline after original-contract completion, termination or abandonment. These HB2237 rules apply to original contracts entered on or after January 1, 2022. Verify the precise claim, notice, filing and service requirements with Texas construction counsel. See Property Code 53.052 and 53.056 and HB2237 effective-date provisions.
• Florida: Covered claimants not in privity generally serve notice to owner no later than 45 days after first furnishing and before final payment under the statutory conditions; recording generally occurs within 90 days after final furnishing. Different claim and service rules apply. See section713.06 and section713.08.

On private projects, lien rights can be a strong collection tool. A sub who misses an applicable notice deadline can lose those rights. Public-project payment bonds follow a separate claim process.

3. Joint check agreements (preventive, requires negotiation upfront)

A joint check agreement requires the GC to issue payment as a check made out to both you and your supplier. Benefits:

• Suppliers extend you better terms because they're not relying on your credit
• You can't accidentally use supplier money for other purposes
• Supplier exposure may fall, but a joint check does not eliminate lien rights. A valid conditional or unconditional waiver is a separate document.

Get joint check agreements set up at contract execution, not after problems arise.

4. Bonding rights (last resort, requires payment bond)

On projects with payment bonds (most public projects, many large private), unpaid subs can claim against the bond. Bond claims have strict notice requirements and timeframes.

5. Pre-qualification and walking away (the most underused leverage)

The single strongest leverage you have is the right to refuse work from GCs with bad payment histories.

Build a database of every GC you've worked with:

• Average days from pay app submission to payment
• Frequency of pay app disputes
• Retainage release history
• Change order responsiveness

GCs who consistently pay over 60 days should be priced higher (or fired), not subsidized with your working capital.

How the best subs play the game

They price for the cash hole

Working capital cost is real. Build it into your bids:

• 30-day GC payment cycle: add 1% to the bid
• 60-day GC payment cycle: add 2% to the bid
• 90-day GC payment cycle: add 3% to the bid
• Plus retainage cost: add 0.5-1% based on retainage percentage and expected hold period

For a $500K project with 60-day pay and 10% retainage, that's an additional $12-15K in your bid. Most subs leave this on the table.

They have an actual line of credit (not credit cards)

A bank line quoted at prime plus 2-3 percentage points is a scenario to compare with actual card APR, fees, collateral and draw terms. A$200-500K line for a$1-3M sub is a planning request, not an underwriting promise. Obtain current lender quotes before comparing cost.

The bank wants to see:

• 2-3 years of profitable financials
• Clean tax filings
• A real bookkeeper (this matters more than people realize)
• AR aging report
• Backlog by GC

If your financials don't support a bank line, this is the work to do, not chasing factoring or credit card limits.

They negotiate supplier terms aggressively

Established subs with payment history can usually get:

• Net-45 from net-30 (15-day improvement)
• Net-60 on key suppliers (30-day improvement)
• Volume discounts that effectively fund the float

A 30-day improvement in supplier terms with a $100K monthly material spend is $100K of permanent working capital improvement.

They invoice every legally permitted milestone

The default AIA cycle is monthly. Some contracts allow biweekly. Some allow milestone billing for substantial deliverables. Check your specific contracts and bill at the maximum frequency allowed.

They aggressively manage retainage

Retainage that ages 18+ months on completed projects deserves a separate quarterly aging review. Confirm release conditions, disputed work, warranty obligations and the payer's solvency. Ordinary notice and lien-perfection windows may already have expired, so an aged balance is not a reason to assume a new lien remains available. Ask construction counsel about contract remedies, applicable retainage-release statutes and any still-timely payment-bond or preserved lien claims.

As an illustrative planning range, a sub might find$50-200K of past-due retainage in its own aging. That is an amount to investigate, not a promised recovery. Contract terms, statutory deadlines, evidence and GC solvency determine the recoverable balance.

They diversify across GCs

At an illustrative30% of revenue from one GC, model the cash effect of that GC paying late. Actual exposure depends on payment timing, margins, backlog, bonds and available financing.

As planning screens, test 4-8 active GC relationships and a 25% single-GC revenue ceiling against your own pipeline and collections. These are advisory limits, not observed stability thresholds. The hero's 15% working-capital exposure screen uses a different denominator and must be tested separately.

What to do when a GC stops paying

Sometimes GCs run into their own cash problems and slow-pay or stop paying. This is an illustrative internal follow-up cadence, never a statutory deadline. Have counsel calendar notice, lien, bond and lawsuit deadlines from the governing trigger dates at contract intake, regardless of invoice age. The escalation:

1. Day 5 past due: Email demand citing prompt pay statute
2. Day 15 past due: Phone call to GC's project manager AND accounting
3. Day 30 past due: Formal letter from your office, certified mail
4. Day 45 past due: Notice of intent to lien
5. Day 60 past due: File mechanics lien (if within statutory window)
6. Day 90 past due: Escalate with construction counsel on enforcement strategy and any available bond claim; counsel should already hold the deadline calendar from contract intake

Each step costs more in relationship damage. But waiting too long forfeits your strongest leverage (lien rights expire). The right answer is usually to escalate faster than feels comfortable.

When the system doesn't work

Sometimes the system genuinely doesn't work, the GC is structurally broken, the project is failing, the owner has run out of money, or there's fraud.

Warning signs:

• GC asking you to "wait one more cycle" repeatedly
• Other subs talking about non-payment
• Project manager turnover
• Site visits showing slowed progress
• GC paying smaller invoices but slow-paying larger ones (cherry-picking)

When these signs appear, promptly confirm still-available remedies and deadlines with construction counsel, preserve evidence and escalate collection. Do not file an unsupported or out-of-time lien.

When to call Level

For subcontractors at the $1-10M revenue level, fractional CFO work focuses on:

• 13-week cash forecasting that incorporates actual GC payment patterns
• Bank line of credit sourcing and structuring
• AR aging and retainage management discipline
• Bid pricing review to recover working capital cost
• Financial-process review of payment terms and deadline tracking alongside construction counsel

Growing from$1-3M revenue can stress working capital, but revenue alone does not define a bankruptcy threshold. Forecasting and collection discipline can help identify exposure. Services and legal coordination depend on the signed engagement.

FAQ

Can I charge interest on late GC payments? Many statutes and contracts provide late-payment interest, but the right, rate, start date and exceptions vary by state, project and contract. Confirm disputed amounts, pay-if-paid terms and the applicable trigger with counsel before adding interest to a demand. A valid interest claim can provide leverage; an assumed 1-1.5% monthly rate is not a statutory entitlement.

What's the cost of a mechanics lien filing? Illustrative budgeting ranges are$50-300 for filing,$250-2,000 for legal help and$200-500 for a filing service. These are unverified planning figures, not current county or vendor prices. Obtain an actual quote, confirm the claim is valid and budget enforcement separately.

How long should I wait before filing a lien? File preliminary notices immediately at project start (these don't damage relationships). Once payment is past due, follow your state's escalation timeline. Don't let lien rights lapse, once the statutory window closes, you've lost your strongest tool.

Should I work for GCs that don't have payment bonds? Bonded projects (mostly public) give you bond claim rights as backup. Unbonded projects rely entirely on lien rights and the GC's solvency. For unbonded private projects, do harder due diligence on the GC and the owner before accepting work.

Related reading:

• AIA Billing and the 25-Day Cash Hole
• How Retainage Kills Contractor Cash Flow
• Why Contractors Bill Millions and Collect Thousands Less