Human sign-off for finance agents, with proof
The approvals desk for your AI agents.
- Replaces
- the approvals-ops person
- For
- AP leads, controllers, payments ops
Countersign is the vertical AI agent for high-stakes finance queues. Your agents do the work. When an action is high stakes, like a vendor bank change or a payout over limit, Countersign puts it in front of the right human with full context, risk flags and the policy that fired, then records a cryptographically signed decision.
Update bank details for Northwind Components GmbH
| IBAN | DE•• 1300 | LT•• 4471 |
| Reply-To | northwind-components.co (9 days old) | |
- ● Bank country changed DE → LT
- ● No callback on record
- ● EUR 61,200 invoice due in 4 days
The problem
Agents can move money. Fraudsters already target the step where a human says yes.
Payment fraud rarely breaks crypto. It talks someone into changing a bank account or releasing a wire. As agents take over AP queues, the human checkpoint gets thinner, and the evidence of who approved what usually lives in email threads and screenshots.
- in reported business email compromise losses in 2024, from 21,442 complaints to the FBI.
- $2.77B[1]
in reported business email compromise losses in 2024, from 21,442 complaints to the FBI.
- of organizations were victims of attempted or actual payments fraud in 2024.
- 79%[2]
of organizations were victims of attempted or actual payments fraud in 2024.
- were targeted by fraudsters impersonating third parties requesting changes to payment instructions.
- 63%[2]
were targeted by fraudsters impersonating third parties requesting changes to payment instructions.
- experienced vendor imposter fraud, up 11 points from the previous survey.
- 45%[2]
experienced vendor imposter fraud, up 11 points from the previous survey.
How it works
Three steps. No new headcount.
Agents propose, they do not execute
Your AP or payments agent sends high-stakes actions to Countersign through one API call, with the evidence it used.
Policy routes it to a human
Bank-detail changes, payouts over limit, duplicates and large runs land in one inbox, with the policy that fired, risk flags and the source email side by side.
Every decision is signed and chained
Approvals and rejections are signed with the approver's device key and appended to a hash-chained log. Export an audit packet anyone can verify.
Live demo
Approve a real decision. Then try to tamper with it.
The demo generates an ECDSA P-256 key in your browser, signs each decision with WebCrypto, chains the log with SHA-256, and catches any edit.
Run it yourself- Simulated AP agent proposes vendor bank changes and over-limit payouts
- Required attestations, like a callback to the number on file
- Hash-chained, signed audit log with one-click verification
- Exportable audit packet with public keys and verification steps
Why now
The window just opened.
20 Mar 2026
Nacha fraud monitoring, phase 1
Large ACH originators must run risk-based processes to catch payments induced by false pretenses, including vendor and BEC impersonation.[3]
2025 survey
Vendor impersonation is rising
Vendor imposter fraud rose to 45% of organizations while classic CEO-style BEC fell to 49%.[2]
2024
BEC remains a top loss category
BEC was the second-costliest crime type in the FBI's 2024 report, behind investment fraud.[1]
Now
Agents are entering AP
Finance teams are piloting agents for invoice capture, matching and payment prep. The approval step is the part that cannot be automated away.
Early access
Early access for finance and payments ops teams.
We are looking for a handful of AP and payments teams running agents, or planning to. Pricing is planned, not final.
Design partner
Design partners$0 during the pilot
Weekly feedback in exchange for free use and roadmap input.
- Up to 3 agents and 10 approvers
- Policy routing and inbox
- Signed, hash-chained audit log
- Audit packet export
Team
$600 per month, planned
Founding price after the pilot.
- Unlimited agents
- SSO and hardware-key signing
- ERP and bank connectors
- Auditor read-only access
FAQ