Once a month, someone in finance asks you the same thing about every job you run: how much more will it cost to finish? Finance calls that your estimate to complete, or ETC, but the plain version is your cost to complete. And if you've ever wondered why finance keeps asking for it, the short answer is this: it's the one number in the whole monthly report that says how the job will actually finish, not how it was bid. Everything else in that report is already on record. Your number is the only piece that reflects the job as it stands today.
That's the whole reason for the ask. This post walks through where your number goes after you hand it over, what happens if it's off, and how to give finance a figure you'd stand behind. One PM's point of view, no accounting class required.
Why does finance care what I think the job will cost to finish?
Finance cares because your cost to complete is the only forward-looking number on the report. The bid said how the job was expected to finish, months ago. Your number says how it will really finish, based on what you can see on site right now. Nobody in the office can produce that. They aren't standing on the job.
Here's the split. A monthly financial report needs two kinds of information about each job. The history (the contract amount, what's been billed, what's been paid, what's been spent) is already in the accounting system, and that's the bulk of it. The one thing the system can't know is how much work is left and what it'll cost. Finance already has the bid, the billing, and every payment on record. Your cost-to-complete is the only piece of the puzzle the system cannot generate on its own (Procore Community, on building a WIP report).
So the ask isn't finance checking up on you. It's the opposite: they're admitting the report literally can't be finished without the person who knows the job. That's you.
Where does my number actually go after I submit it?
Your number becomes the starting point for how much progress the company reports on that job this month. It lands on the WIP schedule (the work-in-progress report finance builds each month from every active job), and from there it drives the job's earned revenue, the amount of the contract the company counts as done so far.
The chain is short. Finance takes what you've spent and compares it to what you've spent plus your cost to complete. That ratio is how far along the job is, and it decides how much of the contract counts as done this month (Foundation Software, on how finance measures job progress). That figure then sets whether the job shows as billed ahead of the work or behind it. From there the finished report goes straight to the bank and the bonding company — the two readers a WIP report is built for (Procore Community, on building a WIP report) — who use it to decide how much work the company can take on next (Grit Insurance, on WIP reporting).
Put plainly: your number drives how much of the job the company counts as done this month, the figure finance reports as progress on the report that goes to the bank or the bonding company. You don't have to track any of that. But it's why a two-minute answer from you matters more than it looks like it should.
What happens if my number is wrong or late?
If your cost to complete comes in too low, the job looks more profitable on paper than it really is. The math reads the job as further along than it is, so it shows more earned profit than the job has actually made. When the real cost finally lands, whether it's a sub bill you knew was coming or a phase that ran long, the profit that was never really there has to come back off. That correction shows up as a surprise instead of something everyone saw building.
That's the honest answer to what happens if my cost to complete is wrong. A cost-to-complete that runs low doesn't make the job any more profitable; it only pushes back the day everyone finds out it isn't. Caught early, the fix is a small adjustment on one month's report. Caught late, it's a chunk of profit vanishing all at once. Earlier is smaller, every time.
A late number causes a different headache. The monthly report can't close until every job is in, so one missing cost to complete holds up the whole thing. If you want the deeper version, the specific reasons a submitted number tends to run low, there's a whole post on it. For now, the takeaway is simple: both problems get easier the sooner your number is real and in.
Is finance expecting a guarantee, or just my best guess?
Just your best guess: a good-faith read on the job today, not a number you're locked into. A cost-to-complete is a forecast, not a promise; updating it next month because the job changed is the professional move, not an admission of a mistake. Finance asks every month because they expect it to move. A number that never changes on a job that clearly did is the one that actually raises eyebrows.
Here's the fear worth naming, because most PMs feel it: you put down $340K in March, the job shifts, and next month it's $410K, and it feels like someone's going to ask, "why'd you say $340K?" That's only a gotcha if you can't say what changed. If you can ("picked up the added foundation work, and the curtain-wall sub claim looks real now"), it's not a gotcha at all. It's you doing your job.
So don't sandbag a number to protect a past one. A moved number with a one-line reason tells finance you're tracking the job. An unchanged number that quietly stopped being true tells them nothing, and it's the one that bites later.
What's the difference between cost-to-complete and cost-at-completion?
They're close, and finance uses both, so it's worth thirty seconds. Cost-to-complete is what's left to spend from today; cost-at-completion is what you've already spent, plus what's left — the expected total for the whole job, start to finish.
| Term | What it means in plain English |
|---|---|
| Cost-to-complete (ETC) | How much more it'll take to finish the job from today |
| Cost-at-completion (EAC) | What you've spent so far, plus what's left — the expected final total |
Using round numbers for illustration: you've spent $400,000 and your cost to complete is $340,000, so your cost at completion is $740,000. Finance only asks you for the first one; they already know what you've spent. If you want the full technical breakdown, including how finance calculates it, that's a separate post. For the field, the one you own is cost-to-complete: what's left to go.
How do I give finance a number I'm comfortable with?
Start from the work that's left, not from a formula. Walk the remaining scope, in your head or across the site, and price it the way you would if you had to finish the job yourself starting tomorrow: the subcontractor balances still owed, the labor hours to go, the material not yet ordered, and the change order everyone's waiting on. Then sanity-check it against what you've already spent. If you're $360K into a $700K job, is another $340K to finish about right? That five-second gut check catches most bad numbers.
Then leave yourself a note. A realistic number with a one-line note beats a round number with nothing behind it. Something like "includes $30K contingency for the outstanding sub claim" takes ten seconds and does two things: it explains the number to finance today, and it explains it to you three months from now when someone re-reads it. That note is professional documentation, not a hedge.
That's the whole task: one honest number, one line of context, on a job you already know cold. Getting the number right is your part; actually getting the number in on time is its own challenge, and there's a separate post on the friction that makes PMs miss the deadline. Either way, your number doesn't disappear into a black hole; this is the step that ultimately builds your company's WIP report, the one the bank and the bonding company read every month.
Frequently asked questions
Why does finance ask for a cost-to-complete every month? Because your cost-to-complete is the one number that says how the job will actually finish, not how it was bid. Finance already has the contract, the billings, and every cost on record — that's history. The cost to finish is the only forward-looking piece, and only the project manager running the job can give it. They ask every month because the job changes every month.
What is the difference between cost-to-complete and cost-at-completion? Cost-to-complete is what's left to spend from today until the job is done. Cost-at-completion is what you've already spent plus what's left — the expected final total for the whole job. If you've spent $400,000 and your cost to complete is $340,000, your cost at completion is $740,000. Finance only asks you for the first one; they already know the rest.
What happens if my cost-to-complete estimate is wrong? If it runs too low, the job looks more profitable on paper than it really is. When the real cost shows up later, the correction lands as a surprise instead of something everyone saw coming. It doesn't make the job better; it only pushes back the day everyone finds out. Catching it early makes the fix smaller, which is exactly why finance asks every month.
Is my cost-to-complete a guarantee, or can it change? It's a forecast, not a promise. Finance fully expects it to move as the job changes — that's why they ask again next month instead of once a year. Updating your number because conditions changed is the professional move, not an admission you got it wrong. A short note explaining what changed is worth more than a number that never moves.
How do I come up with a cost-to-complete number I'm comfortable with? Walk the work that's left and price it honestly: the sub balances still owed, the labor hours to finish, the material still to order, and the change order everyone's waiting on. Then write yourself a one-line note on anything unusual. A realistic number with a one-line note beats a round number with nothing behind it.
How WIP Ready helps
The cost to complete lives in your head and your read on the job; no system produces it for you, which is exactly why finance keeps asking. WIP Ready is built to make handing it over take two minutes instead of a week of follow-up emails: one job per screen, on your phone, no new login, your current costs already on the screen to check against, and a place for your number and your note. It never calculates the number for you. That call stays yours, the way it should be. If you're the one who gets the monthly cost-to-complete email, that's the whole story; see how the check-in works at wipready.com.
