Blog
The accounting firm's guide to vendor bank verification
Knowing how to verify vendor bank details is one of the highest-leverage skills in modern AP. Email can lie; portals can be faked; urgency is cheap. Bank verification is the last line of defense before funds become someone else’s liquidity event.
Why bank verification is the last line of defense
Every upstream control can be perfect on paper—until a single bad instruction reaches the payment rail. Verifying that the beneficiary account matches a trusted, independently confirmed record stops BEC and vendor impersonation at the point of irreversible action.
Manual verification methods
Manual approaches remain valid when applied consistently and documented for audit.
- Callback: Dial a known number from your vendor master—not from the email—to confirm instructions with treasury or AP.
- Confirmation letter: For material relationships, obtain signed bank details on letterhead or through a secure vendor portal with MFA.
- Dual control: Separate preparer and approver for master-file changes; never let one person both receive and verify.
Automated verification
Automation scales what callbacks do in spirit: compare new account and routing data to historical successful payments, flag deviations, and require explicit release for high-risk changes. For firms on QuickBooks Online, that layer pairs naturally with vendor records and bill pay workflows.
Explore vendor verification software built for accounting teams—not generic banking tools bolted onto AP.
Regulatory requirements and professional standards
Exact obligations vary by jurisdiction and client industry, but the through-line is consistent: reasonable care over client funds and vendor disbursements. Document retention, OFAC screening where required, and SOC-minded controls increasingly show up in RFPs and peer reviews. Bank verification evidence strengthens both compliance narratives and insurance discussions.
Best practices for ongoing monitoring
Verification is not a one-time onboarding task. Monitor vendor master changes, re-verify after mergers or treasury reorganizations, and watch for duplicate vendor shells with similar names. Tie monitoring to your accounting stack so alerts fire where staff already work.
Align controls with QuickBooks fraud prevention so QBO remains accurate—and dangerous updates get challenged before payment.
Verify every bank change before it pays
Combine manual callbacks with automated fingerprinting so your last line of defense is consistent, fast, and auditable.