Over-billed or under-billed — which one is hurting your cash?

That gap comes straight off a WIP schedule. Earned revenue comes from percentage-of-completion (POC) — usually cost-to-cost. Below: plain definitions, how each shows up on the WIP and the balance sheet, the overbilling cash trap, underbilling as unbilled AR risk, a labeled example, and what lenders and sureties read into it.

Start here: billed vs. earned

On every active job, two numbers drift apart:

Number	What it is
Billed to date	Invoices / pay apps you've actually sent (not cash collected)
Earned revenue	Contract value × percent complete (work you've performed)
Billing position	Billed − earned → over-billed or under-billed

They're almost never equal, and that's fine. Modest gaps are normal on progress-billed work. Mystery gaps — or the same gap growing every month — are how contractors feel broke while the P&L still says "profit."

If you don't have a current WIP, start there: what is a WIP schedule. If you don't know how earned revenue is calculated, start with POC accounting.

Blackline Financial is construction-only bookkeeping and advisory for contractors and specialty trades (roughly $1M–$30M). We do not prepare tax returns. Job costing, monthly close, and WIP / over-under reporting for Frame-level work live on services — every engagement starts with a DIG Diagnostic, and every package is custom-quoted.

Definitions: over-billing vs under-billing

Term	Meaning	Typical balance-sheet seat
Over-billed (overbilling)	Billings > earned revenue — you've invoiced ahead of completed work	Liability: "billings in excess of costs" / billings in excess of revenue
Under-billed (underbillings)	Earned revenue > billings — you've performed work you haven't invoiced	Asset: "costs and estimated earnings in excess of billings" / underbillings
Job borrow	Chronic / heavy over-billing spent like profit	Cash looks strong; unfinished work still owns that money

Over-billed — how it feels vs what it is. Cash is strong; checks are clearing. What it really is: a liability. You owe the work behind the money. Modest, deliberate over-billing is often healthy cash management — the customer funds the job. Heavy, accidental over-billing is the trap.

Under-billed — how it feels vs what it is. Invisible. The P&L can still look fine. What it really is: you're financing the owner's project. Chronic underbilling is a top reason contractors feel cash-starved on "profitable" books — and sometimes the first symptom that the profit isn't real.

Rule of thumb: slightly over-billed on most jobs is a healthy default. Chronic underbillings, or wild swings month to month, get questions from banks and sureties.

How they appear on the WIP schedule

The over/under column is the point of the WIP — not a footnote.

WIP column	Role
Contract value	Current price including approved change orders
Estimated total cost	Cost at completion — must stay current
Costs to date	Actual job costs posted (job costing)
Percent complete	Usually costs to date ÷ estimated total cost
Earned revenue	Contract × % complete — the POC figure
Billed to date	Draws / pay apps sent
Over / under billing	Billed − earned — this page's subject

One row per job. The portfolio total of that last column is what your bonding agent is scanning. Full column walkthrough: WIP schedule. How earned hits the books: percentage-of-completion.

How they appear on the balance sheet

When the monthly close posts POC and billing-position entries, the gap doesn't stay on a side spreadsheet — it hits the balance sheet.

Over-billing (liability). Billings in excess of costs (or billings in excess of revenue earned) sits with other liabilities. It says: customers have paid (or been billed) ahead of performance. That liability shrinks as you complete the work or as you reverse over-billing in later periods. Treating the cash as free equity is how job borrow starts.

Under-billing (asset). Costs and estimated earnings in excess of billings — underbillings — sit as an asset. It says: you've earned (and often spent) more than you've invoiced. Healthy underbilling clears next cycle when you send the pay app. Sticky underbilling is either unbilled AR you haven't chased, unapproved change orders you can't bill yet, or margin fade wearing a timing problem's clothes.

The statement names for those lines are explained on costs in excess of billings.

Not the same as AR. Accounts receivable is invoices sent and not yet collected. Underbillings is work earned and not yet invoiced. You can be current on AR and still drowning in underbillings — different problem, different fix. Retainage billed but held is still "billed" on the WIP; track retainage separately for cash timing.

Over-billing: the cash-flow trap that feels like winning

Over-billing often happens on purpose — a front-loaded schedule of values, mobilization billing, an aggressive first draw. In moderation, that's a tool: your customer funds the work instead of you.

The trap is what over-billed cash does to judgment. It sits in the same bank account as everything else and looks like money you've made. It isn't — it's money collected for work you still owe. Contractors get hurt when they spend it like profit: trucks, a bigger shop, an early distribution. Then the over-billed jobs enter the final stretch, costs keep coming, there's almost nothing left to bill — and payroll gets tight on jobs that were "always profitable."

Accountants call this job borrow: the front of the job lends you cash; the back takes it back. If you don't know how much of your bank balance belongs to unfinished work, you don't know how much cash you actually have. Pair the WIP with a 13-week cash flow so borrowed job cash doesn't get planned as free float.

Healthy vs. dangerous over-billing:

Signal	Read
Modest, deliberate front-load that still leaves billable value at the back	Usually fine — customers funding the job
Over-bill growing while estimated GP is shrinking	Danger — hiding fade in billings
Cash spent on overhead/distributions equal to the over-bill	Job borrow — the back half will confess
Surety / bank sees consistent slight over-bill with stable EACs	Discipline

Under-billing: unbilled AR risk (and sometimes a margin problem)

Under-billing almost never happens on purpose. It creeps in through:

1. Slow billing cycles — work finished in March; invoice out in May.
2. Missed draws — a pay-app deadline slips and you wait a full cycle.
3. Unapproved change orders — extra work done, not on paper, so you can't bill it.
4. Cost overruns nobody has faced — costs climb faster than the estimate, which inflates percent complete and makes "earned" outrun what you can actually invoice.

That last one matters: sometimes underbilling isn't a billing problem at all — it's the first visible symptom of a job that's losing money (profit fade). The reflex "we'll just bill harder" isn't always the fix. First ask: is this work we can invoice next cycle, or cost we can never bill for? One is timing. The other is a margin problem wearing a timing problem's clothes — often born at bid time from confusing markup vs margin.

Underbillings as risk:

Kind of under-bill	What to do
Missed / late pay app	Bill this cycle — treat a missed draw like missed payroll
Unapproved CO	Paper the CO before (or immediately after) the work; don't let "underbillings" mean unbillable
Estimate / fade	Update EAC honestly on the WIP; POC will recognize the bad news — that's a feature
Chronic portfolio under-bill	Process problem: billing calendar, CO discipline, or books that can't support a monthly WIP

Fade analysis lives on the same schedule that drives POC — estimated GP and EAC changes across periods. There is no separate magic report. See POC accounting — gain and fade and WIP schedule.

Labeled example (illustrative only)

Example only — not a client case, not a quote. Three open jobs at month-end:

Illustrative only. Not a client case, not a quote.

How to read it:

• Job A — Meaningful over-billing. Cash is ahead of work. Fine if the schedule of values still has billable value left and nobody spent the $80K like profit. If estimated cost-at-completion is quietly climbing toward $900K, that over-bill is papering over fade.
• Job B — Act this week: $90,000 under-billed. If that's a missed pay app or unapproved COs, bill or paper it. If costs should be $540K at completion instead of $480K, percent complete drops, earned drops, and part of that "under-bill" was never billable — margin problem, not timing.
• Job C — Slight over-bill; healthy default. Keep estimates honest as costs land.

Balance-sheet sketch (illustrative): Jobs A + C contribute to a billings-in-excess liability (~$87,500 combined over). Job B sits as an underbillings asset ($90,000) until you invoice or face the estimate. Net portfolio looks nearly flat — which is exactly why job-level WIP beats a single company-wide guess.

Stack this read every month as part of close (how we close), not the week before a bonding packet is due.

What lenders and sureties read into billing position

Banks and bonding agents look at billing position early, because it tells them whether profit is trustworthy:

• Slight, consistent over-billing — reads as discipline. You bill ahead, manage cash, customers fund the work.
• Chronic underbillings — classic red flag. Slow billing at best; unapproved COs or fading jobs at worst.
• Big swings between periods — estimates (or books) that can't be relied on.
• Clean monthly WIP + modest over-billed position — capacity conversations go smoother than a mystery under-billing number built the week before renewal.

Contractors who walk in with a current schedule and honest EACs get questions they can answer. Contractors who don't get capacity held back.

How to stay in the healthy zone

1. Run a WIP schedule monthly — not quarterly. Billing position is only fixable while the job is still open (WIP schedule).
2. Front-load deliberately, not accidentally — a sensible schedule of values that covers mobilization is a tool; hiding losses in over-billing is a time bomb.
3. Bill everything, every cycle — hard internal pay-app deadline; treat a missed draw like a missed payroll.
4. Paper every change order before the work — unapproved COs are the biggest source of "underbilling" that turns out to be unbillable.
5. Update cost-to-complete estimates honestly — a stale estimate poisons percent complete, earned revenue, and the over/under column (POC).
6. Track job borrow — know how much of your bank balance belongs to unfinished work before you spend it; use a 13-week cash flow so over-billed cash isn't planned as free.

This only works on construction books: complete job costing, honest estimates, and a disciplined close. A pretty over/under number on unreconciled accounts is fiction with a label.

FAQ

What is over-billing vs under-billing in construction?

Over-billing (over-billed) means you've invoiced more than you've earned on a job — billings exceed earned revenue. Under-billing (underbillings) means you've earned more than you've billed — you're financing work not yet invoiced. Both come from the WIP schedule: billed minus earned.

How do overbilling and underbillings show up on the balance sheet?

Over-billing typically appears as a liability (billings in excess of costs / billings in excess of revenue). Underbillings typically appear as an asset (costs and estimated earnings in excess of billings). They are not the same as accounts receivable — AR is invoiced and unpaid; underbillings is earned and not yet invoiced.

Is over-billing always bad for contractors?

No. Modest, deliberate over-billing is often healthy cash management — customers fund the job. The trap is spending over-billed cash like profit (job borrow), then hitting the back half of the job with costs still coming and little left to bill.

What causes underbillings?

Slow billing, missed draws, unapproved change orders, and cost overruns that inflate percent complete so "earned" outruns what you can invoice. Ask every time: can we bill this next cycle, or is this unbillable cost (a margin / fade problem)?

How do over/under billing tie to WIP and percentage-of-completion?

Same math, three seats. POC sets earned revenue; the WIP schedule shows billed vs earned by job; over/under is the gap — posted to the balance sheet at close. Blackline can maintain that monthly close for construction businesses — contact or services; we don't prepare tax returns.