Positive Pay for Construction and Contractor Businesses
Construction and contractor businesses move a large share of their money by paper check. General contractors pay subcontractors on draw schedules, settle supplier and material invoices, cut checks to equipment rental companies, and cover progress payments tied to lien waivers. Many of those checks are mailed, handed off on a job site, or sent to a payee the office has never met. That mix of high dollar amounts and loosely controlled handling is exactly what check fraud targets.
Positive pay is a bank service that checks every paper item against a list of checks you actually issued. You upload a check-issue file, and the bank compares each presented check to it. Anything that does not match becomes an exception you review before money leaves the account.
Who construction businesses pay, and why those checks get hit
A single project can involve dozens of separate companies that all need to be paid: subcontractors, material suppliers, equipment rental firms, and independent crews. Payments are large, recurring, and often released against a pay application or a signed lien waiver. That creates several openings fraudsters use:
- Mailed checks to suppliers and subs. A check sitting in a mailbox can be stolen and check-washed, where the original ink is removed so the amount and payee can be rewritten.
- Predictable, high-value payments. Draw schedules and monthly supplier runs mean fraudsters can guess roughly when a large check is in the mail.
- Vendor impersonation. Someone poses as a known subcontractor or supplier and requests payment or new remittance details, a tactic that overlaps with business email compromise.
- Stolen blank check stock from a job-site trailer or an unsecured office.
Check fraud is not a niche problem. According to the 2026 AFP Payments Fraud and Control Survey, 76% of organizations experienced attempted or actual payments fraud in 2025, and 58% reported that checks were subject to fraud, making checks the payment method most frequently impacted (Association for Financial Professionals, 2026). Construction firms write a lot of checks, so they carry a lot of that exposure.
How positive pay and payee positive pay protect you
Standard positive pay matches three things on each presented check against your issue file: the account number, the check number, and the amount. If a stolen check is cashed for a different amount, or a check number you never issued shows up, the bank flags it as an exception and you decide whether to pay or return it.
Payee positive pay adds the payee name to that comparison. This matters in construction because check washing often leaves the amount alone and only changes the payee, redirecting a legitimate subcontractor payment to the thief. When the bank also verifies the payee name against your file, an altered payee gets caught even if the dollar amount looks correct. If your bank offers payee match, use it. You can read more in our overviews of how positive pay stops check fraud and payee positive pay.
Positive pay does not stop a check from being stolen. It stops a fraudulent or altered check from clearing your account by giving you a window to return it. Pair it with secure check stock, prompt mailing, and reconciliation, and consider reporting voided checks so canceled items cannot be cashed.
Producing the check-issue file from your accounting software
Most construction back offices run on accounting or job-costing software such as QuickBooks, Sage, Foundation, or a similar package. The workflow is the same in each: after you release a check run, export the list of issued checks and turn it into the layout your bank accepts.
- Run your check batch in your accounting software, then export the issued checks (usually check number, date, amount, and payee).
- Open the free positive pay file generator and load that export.
- Map your columns to the fields your bank wants, then download the file in the exact format your bank requires.
- Upload it to your bank's treasury portal before the daily cutoff.
Banks differ on whether they expect a fixed-width file or a CSV, and on the exact field order, the date format, and how the amount is written. Some use an implied decimal with no decimal point. Because the layout is account-specific, we do not publish a single universal spec. The positive pay file format reference explains the common fields, and the generator's format library covers many banks. If yours is not listed, the custom format builder lets you match your bank's layout field by field. If you run QuickBooks, see the QuickBooks positive pay guide.
Verify your first file before you rely on it
A check-issue file only protects you if the bank can read it. The most common reasons a file gets rejected are a wrong date format, a misaligned column in a fixed-width layout, or an amount written with the wrong decimal handling.
- Run a small real batch and compare every field against your bank's written specification.
- Confirm the amount format matches: dollars and cents, with or without a decimal point, as your bank requires.
- Make sure the totals and check count tie back to what your accounting software printed.
- Use the built-in file validator to catch structural errors before you upload.
- Submit the first file early so you have time to fix and resend if it is rejected.
Once your bank confirms the file imports cleanly, repeat the same export-and-generate steps for every check run. For background on the service, see what is positive pay.