For bookkeeping & accounting firms

Every vendor bank-detail change, verified the same way — and documented.

CallbackProof turns "call the vendor back on a known number" from an ad-hoc habit into an enforced checklist with a tamper-evident audit log — across every client your firm manages. When an insurer or auditor asks for your callback procedure, you hand them the record.

No card required. Set up your first client in minutes.

The request arrives by email

"Our bank details changed — please update before the next payment." Your team fields these every week, for dozens of clients. Most are real. The procedure has to be the same either way.

The control everyone recommends

Call the vendor back on a number you already had on file — never one from the request — and have a second person sign off. The hard part isn't knowing this. It's doing it consistently and proving you did.

The documentation gap

Cyber-insurance applications and auditors increasingly ask for a documented callback procedure. Scattered emails and sticky notes aren't a record. CallbackProof is.

How the verified callback works

A case can only reach Verified by completing every step. The order is enforced, and every action lands in an append-only, hash-chained log with server-side timestamps.

  1. 1

    Open a case

    A change request comes in — by email, phone, or your client’s intake link. Record what changed, who asked, and the last 4 digits of the new account. Never the full number.

  2. 2

    Source a known-good contact

    Pull the vendor’s phone number from your own records — the vendor file, a prior invoice, the official website. Never from the change request itself. Record where it came from.

  3. 3

    Make the callback

    Call the vendor on that independent number. Log who called, the number dialed, who answered, and whether they confirmed the change.

  4. 4

    Second-person approval

    A second firm user reviews the case and approves. Solo practice? An explicit solo override is allowed — and permanently recorded as such.

The output: a clean PDF verification record per case — checklist, callback details, approvals, and the full tamper-evident log — plus one-click exports of all cases for a client or date range when an insurer or auditor asks.

Built for firms that run AP for many clients

Per-client intake links

Give each client a shareable form. Their staff submit change requests in a structured way — no logins, rate-limited — and each submission opens a draft case for your review.

Tamper-evident audit log

Every case action is appended to a SHA-256 hash-chained log with server-side timestamps. No edits, no deletions — corrections are new entries. Integrity is checkable at any time.

Enforced order of steps

The callback can’t be logged before an independent contact is recorded. Approval can’t happen before the callback. The checklist is the workflow.

Dashboard across all clients

Open cases, overdue verifications, and per-client counts in one place. Email notifications when a case is assigned, awaiting second approval, or arrives via intake.

Insurance & audit exports

One click: all cases for a client or date range as a PDF pack plus CSV — exactly what you hand over when asked for your documented procedure.

Minimal sensitive data

CallbackProof stores only the last 4 digits of any account number, ever. Evidence files live in a private bucket and are shared only via expiring signed links.

Pricing

14-day free trial on both plans. No card required to start.

Starter

$99/mo

  • ✓ Up to 25 clients
  • ✓ Unlimited cases and users
  • ✓ Enforced checklist + audit log
  • ✓ Intake links, PDF records, exports
  • ✓ Email notifications
Start free trial

Firm

$199/mo

  • ✓ Everything in Starter
  • ✓ Unlimited clients
  • ✓ Your firm's name and logo on PDF records
Start free trial

One misdirected vendor payment typically costs more than a decade of CallbackProof. Billing is handled by Lemon Squeezy (merchant of record); cancel anytime.

What CallbackProof is — and isn't

CallbackProof is a documentation and workflow tool. It enforces your verification checklist and produces a defensible record of the steps your firm performed. It does not validate bank-account ownership, does not screen or block payments, and is not a fraud-prevention service or guarantee. Judgment about whether to act on a change request always remains with your firm.