Positive pay files in Dynamics 365 Finance

How F&O generates positive pay files for bank fraud prevention — file formats, daily transmission, reconciliation, and the typical bank-specific variations.

Updated 2026-09-15

Positive pay is a bank fraud-prevention service: each day, the company sends the bank a list of legitimately issued checks; the bank rejects any check presented that's not on the list. For US companies with check-based AP, positive pay is the standard control. F&O supports positive pay file generation through configurable data exchanges.

The threat being mitigated.

  • Check fraud — stolen checks, altered amounts, counterfeit checks presented for payment.
  • Without positive pay — bank pays anything that looks like a valid check.
  • With positive pay — bank validates against the issuer's daily list.

For companies issuing thousands of checks monthly, positive pay is essential.

Positive pay file contents. Typical fields per record:

  • Account number.
  • Check number.
  • Check amount.
  • Issue date.
  • Payee name.
  • Void status (for cancelled checks).

The bank validates each presented check against the file.

Configuration in F&O.

  • Bank account flagged for positive pay.
  • Bank file format configured (data exchange definition).
  • Positive pay record generated on check issuance.

When a check is printed, a positive pay record is created. End-of-day, the records flow to a file.

Generating the file. Generate positive pay file action:

  1. Selects records since last submission.
  2. Formats per bank's specification.
  3. Outputs file (CSV, fixed-width, XML, etc. depending on bank).
  4. Marks records as submitted.

Bank-specific formats. Every bank has its own format:

  • Chase — specific layout.
  • Bank of America — different.
  • Wells Fargo — different again.
  • JPMorgan — different.

F&O ships with templates for major banks; customisation needed for others. The configuration is a data exchange definition mapping F&O records to bank's expected fields.

Transmission methods.

  • Bank portal upload — manual; operator uploads daily.
  • FTP/SFTP — automated transmission to bank's SFTP server.
  • Bank API — modern; programmatic.
  • EDI — for some banks.

Automation reduces operational burden; without it, daily manual upload is a chore.

Exceptions. When the bank receives a check not on the list:

  • Exception alert to the company.
  • Hold for review — company decides accept or reject.
  • Timeout default — if no response, bank's default (often reject).

The company reviews exceptions daily; legitimate checks (rare misses) get authorised, fraudulent ones rejected.

Stop payments. When a check is voided:

  • Stop payment record sent to bank.
  • Bank rejects if presented.
  • Positive pay file may include void instructions.

Reverse positive pay vs payee positive pay.

  • Standard positive pay — match on account, check number, amount.
  • Payee positive pay — also match payee name; harder to defeat.

Many banks offer both tiers; payee positive pay is stronger but requires accurate payee name capture.

Daily transmission rhythm. Critical:

  • Send positive pay file BEFORE any check could be presented.
  • Banks typically require file by 8 AM or so for that day's presentments.
  • Late files = checks presented before listing = potential acceptance of fraudulent items.

The cutoff is bank-specific; verify and respect.

Reconciliation against bank. Beyond positive pay:

  • Bank statement received daily / monthly.
  • Match cleared checks against F&O bank ledger.
  • Investigate items not matching.

Positive pay catches fraudulent checks at presentment; bank reconciliation catches issues post-clearing.

ACH positive pay. Beyond checks, ACH transactions can also use positive pay:

  • ACH originators authorised.
  • Unauthorised ACH debits blocked.

F&O supports ACH positive pay configuration similarly.

Implementation considerations.

  • Bank partnership — bank must support positive pay (most do).
  • File format provisioned — bank's specification implemented in F&O.
  • Transmission method — FTP / API setup.
  • Exception handling process — who reviews exceptions, how quickly.

Common pitfalls.

  • File late. Daily transmission missed; window of fraud opportunity.
  • Format errors. File rejected by bank; checks not validated; revert to manual.
  • Stop payment not transmitted. Voided check reaches bank; pays out as positive pay-listed.
  • Payee name mismatch. "John Smith" vs "Smith, John"; payee positive pay flags legitimate checks.
  • No exception review. Bank rejects valid checks; vendor calls; AP scrambles.
  • Manual override drift. Operator approves exceptions routinely without analysis.

Operational rhythm.

  • Daily — file transmission, exception review, monitoring.
  • Weekly — process audit; missed file investigations.
  • Monthly — reconcile bank's records of presented vs our records of issued.

Strategic positioning. Positive pay is a high-leverage fraud control — relatively cheap to set up, dramatically reduces check fraud risk. For any US company issuing checks at scale, it's a standard expectation. F&O supports it natively with appropriate bank format configuration; the operational discipline of timely transmission and exception review is what makes it effective. The decision to NOT use positive pay rarely makes sense for check-issuing companies; the implementation is small, the protection material.

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