---
title: "What is Account takeover (ATO)? Definition"
description: "Account takeover is when a criminal gains control of a legitimate account - an email mailbox, a vendor portal login or an online banking user - and..."
url: https://realpayee.com/glossary/account-takeover
canonical: https://realpayee.com/glossary/account-takeover
date_published: 2026-10-05
date_modified: 2026-10-05
author: RealPayee
---

# Account takeover (ATO)

> Account takeover is when a criminal gains control of a legitimate account - an email mailbox, a vendor portal login or an online banking user - and uses it to act as the real owner. In vendor fraud, a taken-over supplier mailbox lets the attacker request bank changes on genuine email threads.

_Published 2026-10-05 · Updated 2026-10-05 · By RealPayee_

## Related terms

- [Business email compromise (BEC)](https://realpayee.com/glossary/business-email-compromise): Business email compromise is fraud in which criminals use spoofed, lookalike or hijacked business email to trick employees into sending money or sensitive data.
- [Vendor impersonation fraud](https://realpayee.com/glossary/vendor-impersonation): Vendor impersonation fraud is when a criminal poses as a real supplier - usually by compromised or lookalike email - to redirect its payments to a new bank account.
- [Social engineering](https://realpayee.com/glossary/social-engineering): Social engineering is manipulating people - rather than hacking systems - into breaking normal procedures, typically through authority, urgency, secrecy or familiarity.

## Why it matters for finance teams

Most payment fraud reaches AP as a request that looks legitimate. Understanding account takeover helps your team spot it and apply the right control: verify bank-detail changes and large payment requests with the real person, out-of-band, before money moves. Our free [bank-change policy template](https://realpayee.com/templates/vendor-bank-change-policy) puts that into a written rule.

Full glossary: https://realpayee.com/glossary · All terms as JSON Lines: https://realpayee.com/feeds/glossary.jsonl

## Related

- [Vendor fraud: types, examples and how to prevent it](https://realpayee.com/vendor-fraud) - What vendor fraud is, the most common schemes (vendor impersonation, fake bank changes, fake invoices) and the controls that stop them. (markdown: https://realpayee.com/vendor-fraud.md)

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