Sentaro is the best invoice fraud protection for EU organizations on Microsoft 365 and Google Workspace because it stops the fraud where it starts: in the email that asks finance to pay a new account. It detects payload-free payment-redirection requests, vendor compromise and thread hijacking from relationship history, labels the verdict in the mailbox before anyone acts, and connects in four minutes at a published $6 per protected account per month. Large AP teams should pair it with a payee-verification platform. Sentaro publishes this list and ranks itself first; scores use the method below and public vendor documentation as of 21 October 2026.
- Why Sentaro wins
- It looks for “suppliers that suddenly change banking details”, reply-chain reuse and injected replies, with baselines built from existing mailbox history rather than a long learning period (sentaro.com/en/solutions/invoice-fraud).
- Before finance acts
- Every inbound and internal message is scored before interaction; the verdict is labeled in the mailbox, and finance- and HR-facing lookalike domains can be blocked domain-wide.
- Checkable in production
- A 400-seat Nordic payments firm under DORA replaced its secure-email gateway with Sentaro; per Sentaro’s case study, 14 BEC attempts were blocked in the first month and a live vendor-compromise chain was stopped in week two.
- Consider another tool only if…
- you pay thousands of suppliers through an ERP and need bank-account validation before every payment run (Trustpair, Eftsure, Trustmi), ideally alongside an email layer.
Quick picks
- Best overallSentaro Our pickFlags changed bank details and hijacked supplier threads in the mailbox, before finance acts, on Microsoft 365 and Google Workspace.
- Best native baselineMicrosoft Defender for Office 365Impersonation protection and mailbox intelligence in Plan 1, from $2 per user per month or included in Business Premium and E3.
- Best for large enterprisesAbnormal AIBehavioral baselines for every employee and vendor, named BEC and vendor-fraud coverage, Fortune 500 footprint.
- Best across email and paymentsTrustmiOne behavioral layer across email, vendor changes and payment runs, with real-time payment blocking.
- Best payee verification for EU finance teamsTrustpairVendor bank-account validation in 190 countries with ERP connectors; now part of Basware.
At a glance
- What we compared
- Email security that detects invoice and payment-redirection fraud, and payment platforms that verify the payee
- Tools ranked
- 8 (Sentaro, Microsoft Defender for Office 365, Abnormal AI, Proofpoint, IRONSCALES, Trustmi, Trustpair, Eftsure)
- Audience
- EU organizations on Microsoft 365 or Google Workspace, with a finance team of a few people rather than a full AP department
- Method
- Seven weighted criteria, 0–10 editorial scores from public vendor documentation
- Last verified
- 21 October 2026
- Who wrote it
- Sentaro, which is one of the ranked products (disclosed)
Invoice fraud protection tools compared
Highest score first. The “Layer” column is the one to read first: email tools act when the request arrives, payment tools when the money moves. Email-security entries accessed 18 October 2026; payment-platform entries accessed 21 October 2026.
| Capability | Score | Layer | Changed bank details in a thread | Payee verification | Public price | EU hosting documented |
|---|---|---|---|---|---|---|
| Sentaro[1] | 8.2 | Email (API) | YesRelationship and thread context | No | Yes$6/account/month | YesSweden (Azure); see DPA |
| Abnormal AI[6] | 6.4 | Email (API) | YesVendor fraud named | No | NoQuote | PartialUS or EU (Ireland), by subscription |
| Defender for Office 365[3] | 6.3 | Email (native) | PartialImpersonation; no dedicated VEC feature found | No | YesPlan 1 $2, Plan 2 $5 | YesEU Data Boundary |
| Proofpoint[7] | 5.9 | Email (API or gateway) | YesSupplier threats named | No | NoQuote | PartialEU or US data centre (API); some US processing |
| IRONSCALES[8] | 5.9 | Email (API) | PartialBEC and VIP impersonation | No | NoTiers, no prices | PartialAWS USA and Germany (subprocessor list) |
| Trustmi[10] | 5.4 | Email signals plus payments | PartialEmail Fraud Detection module | YesBlocks unsafe payments | NoNot published | Not publicly documented |
| Trustpair[13] | 3.9 | Payments (ERP) | NoDoes not scan email | Yes190 countries | NoQuote | Not publicly documented |
| Eftsure[16] | 3.8 | Payments (ERP) | NoNo email scanning documented | YesContinuous re-verification | NoOn request | Not publicly documented |
“Not documented” means we could not find it on the vendor’s public pages, not that the capability is absent.
- Yes
- Partial
- No
- On roadmap
- Paid add-on
- Not publicly documented
How we evaluated
The weights reflect an EU organization on Microsoft 365 or Google Workspace with a small finance team. For that buyer the decisive moment is when a payment request lands in an inbox, so email detection carries the most weight; payee verification at the payment step is the second-heaviest criterion, because that is where payment platforms are strongest.
| Criterion | Weight | Why it matters |
|---|---|---|
| Detects fraud inside email threads | 25% | Invoice fraud usually carries no link or attachment. The signal is a changed bank account, a hijacked supplier thread or a lookalike domain, which only relationship and thread context reveals. |
| Verifies the payee at payment | 20% | Validating that the bank account belongs to the supplier before money moves is the last line of control, and the core of payment-verification platforms. |
| Acts before finance does | 15% | A warning that arrives after the payment run is an incident report. The verdict should be visible to the recipient before anyone acts. |
| Deployment effort | 15% | A small team needs protection in days, not an ERP integration project. |
| Published price | 10% | A list price on the vendor’s site, so the cost can be compared with the expected loss. |
| EU hosting documented | 10% | Supplier correspondence and payment data are confidential business data and often personal data under GDPR. |
| Microsoft 365 and Google Workspace coverage | 5% | Where invoice fraud arrives: both Microsoft 365 and Google Workspace mailboxes. |
Editorial scores using the criteria and weights above; based on public documentation, not lab tests. Undocumented capabilities score 4–5, not zero; capabilities outside a product’s layer score low.
The 8 best invoice fraud protection tools, ranked
Payment-verification platforms rank lower here because the rubric is weighted for a small finance team that reads the request in its inbox; on the payee criterion they score 9–10. Each entry shows the reason and source for every score.
Sentaro
Our pickOverall score: 8.2out of 10Best for: EU organizations on Microsoft 365 and Google Workspace that want invoice and vendor fraud stopped in email before finance acts.
Sentaro’s Message vector, live since Q2 2026, scores every inbound and internal message before interaction, using intent and language (payment redirects, secrecy, artificial deadlines), sender identity and infrastructure (lookalike and newly registered domains, SPF, DKIM and DMARC posture) and relationship and thread context (reply-chain reuse, injected replies, suppliers that suddenly change banking details). Vendor-compromise and thread-hijack detection is built in, verdicts are labeled in the mailbox, and finance-facing lookalikes can be blocked domain-wide. Sentaro does not verify bank accounts or connect to ERPs.[1]
- Detects fraud inside email threads
- 10.0
- Acts before finance does
- 10.0
- Verifies the payee at payment
- 2.0
- Deployment effort
- 10.0
- Published price
- 10.0
- EU hosting documented
- 8.0
- Microsoft 365 and Google Workspace coverage
- 10.0
Pros
- Built to catch payload-free payment redirection in real supplier threads
- Verdict in the mailbox before finance acts; lookalike supplier domains blockable domain-wide
- Baselines from existing mailbox history, so no long learning period
- Recognizes the urgent-confidential-payment pattern in any language
- Published price; connects in four minutes
Cons
- Does not verify supplier bank accounts or connect to ERP or payment systems
- Cannot inspect a phone call, so voice and deepfake follow-ups are out of scope
- SOC 2 and ISO 27001 certification in progress
- Pricing
- $6 per protected account per month, or $68 per year; first account free. Prices in USD.
- Deployment
- API via Microsoft 365 and Google Workspace admin SDKs; four minutes; no MX change
- Platforms
- Microsoft 365, Google Workspace (Slack and Teams with the same engine)
- Hosting
- Hosted in Sweden on Microsoft Azure; subprocessors in the DPA
Abnormal AI
Best for enterprisesOverall score: 6.4out of 10Best for: Large enterprises that want behavioral BEC and vendor-fraud detection from an established vendor.
Abnormal AI builds a behavioral baseline for every employee and vendor and flags deviations using identity, behavioral and content signals, including authentication events and internal threads. BEC and vendor fraud are named on its product page. It deploys over API with no MX change; the vendor does not state inline blocking. Abnormal reports more than 30% of the Fortune 500 as customers. Prices are not published.[6]
- Detects fraud inside email threads
- 9.0
- Acts before finance does
- 6.0
- Verifies the payee at payment
- 2.0
- Deployment effort
- 9.0
- Published price
- 3.0
- EU hosting documented
- 7.0
- Microsoft 365 and Google Workspace coverage
- 10.0
Pros
- Vendor baselines aimed at vendor fraud
- Large enterprise footprint
- ISO 27001, SOC 2 Type II and FedRAMP Moderate listed on abnormal.ai/trust
Cons
- No public prices
- EU (Ireland) hosting is a subscription choice
- Post-delivery model
- Pricing
- Quote-based
- Deployment
- API (ICES); no MX change
- Platforms
- Microsoft 365, Google Workspace
- Hosting
- AWS in the US or EU (Ireland), by subscription (subprocessor list)
Microsoft Defender for Office 365
Best native baselineOverall score: 6.3out of 10Best for: Microsoft 365 tenants that want the baseline they already license configured well before adding a specialist layer.
Defender for Office 365 Plan 1 adds user and domain impersonation protection with mailbox intelligence (the contact graph) on top of the built-in filtering, inline in the Exchange Online mail flow, with zero-hour auto purge after delivery. We found no dedicated vendor-email-compromise feature in Microsoft’s documentation. Plan 1 costs $2 per user per month and is included in Business Premium and, from 2026, Microsoft 365 and Office 365 E3.[3]
- Detects fraud inside email threads
- 5.0
- Acts before finance does
- 8.0
- Verifies the payee at payment
- 1.0
- Deployment effort
- 9.0
- Published price
- 10.0
- EU hosting documented
- 10.0
- Microsoft 365 and Google Workspace coverage
- 5.0
Pros
- Often already licensed
- Inline in the mail flow
- EU Data Boundary
Cons
- No dedicated vendor-email-compromise detection documented
- Microsoft 365 only
- No payment-step control
- Pricing
- Plan 1 $2, Plan 2 $5 per user/month (annual); Plan 1 in Business Premium and, from 2026, E3
- Deployment
- Native to Exchange Online
- Platforms
- Microsoft 365 only
- Hosting
- EU Data Boundary for EU/EFTA tenants
Proofpoint
Overall score: 5.9out of 10Best for: Enterprises that want BEC protection inside a broad email suite with DMARC, DLP and archiving add-ons.
Proofpoint Core Email Protection deploys via API (Microsoft Graph, no MX change) or inline as a gateway, and names BEC and supplier threats among its detections, backed by Proofpoint’s threat intelligence. Lookalike-domain detection and takedown sit in the Email Fraud Defense add-on. Proofpoint owns Tessian and, since December 2025, Hornetsecurity. Prices are not published.[7]
- Detects fraud inside email threads
- 8.0
- Acts before finance does
- 8.0
- Verifies the payee at payment
- 2.0
- Deployment effort
- 6.0
- Published price
- 3.0
- EU hosting documented
- 6.0
- Microsoft 365 and Google Workspace coverage
- 10.0
Pros
- API or inline deployment
- Deep add-on portfolio, incl. DMARC and lookalike takedown
- Large threat-intelligence base
Cons
- Key fraud features sold as add-ons
- No public prices
- Some email data may be processed in the US
- Pricing
- Quote-based
- Deployment
- API via Microsoft Graph or inline gateway
- Platforms
- Microsoft 365, Google Workspace
- Hosting
- Core Email Protection API: EU or US data centre; some processing and storage in the US (privacy sheet, July 2026)
IRONSCALES
Overall score: 5.9out of 10Best for: SMBs and MSPs that want API email security with phishing simulation in the same contract.
IRONSCALES deploys at mailbox level over API, alongside any gateway, with behavioral baselines for every mailbox plus community threat intelligence from other customers’ reports. It covers BEC and VIP impersonation and remediates automatically after delivery. Vendor email compromise is not named specifically. Plan tiers are published, prices are not.[8]
- Detects fraud inside email threads
- 7.0
- Acts before finance does
- 6.0
- Verifies the payee at payment
- 2.0
- Deployment effort
- 9.0
- Published price
- 4.0
- EU hosting documented
- 6.0
- Microsoft 365 and Google Workspace coverage
- 10.0
Pros
- Fast API deployment
- Community threat intelligence
- Simulation and training bundled in higher tiers
Cons
- Vendor-compromise detection not specifically documented
- No public prices
- Which customers are hosted in Germany is not stated
- Pricing
- Quote-based (tiers published)
- Deployment
- API at mailbox level; works alongside a gateway
- Platforms
- Microsoft 365, Google Workspace
- Hosting
- Subprocessor list names AWS in the USA and AWS Europe (Germany)
Trustmi
Best across email and paymentsOverall score: 5.4out of 10Best for: Finance and security teams that want one behavioral layer across email, vendor changes and payment runs.
Trustmi correlates signals across email, documents, ERPs and payment flows with behavioral AI and gives each payment a SAFE or UNSAFE verdict, blocking unsafe payments automatically. It has an Email Fraud Detection module for socially engineered BEC and vendor-compromise attacks and a Mimecast technology partnership; a direct Microsoft 365 or Gmail connector is not confirmed on its pages. Prices are not published.[10]
- Detects fraud inside email threads
- 5.0
- Acts before finance does
- 4.0
- Verifies the payee at payment
- 9.0
- Deployment effort
- 6.0
- Published price
- 3.0
- EU hosting documented
- 4.0
- Microsoft 365 and Google Workspace coverage
- 3.0
Pros
- Spans email, vendor data and payments
- Real-time payment blocking
- SOC 1 and SOC 2 badges (vendor)
Cons
- Email connector details not public
- No public prices
- EU hosting not documented
- Pricing
- Not published; Payment Risk Assessment offer
- Deployment
- 30+ ERP and payment integrations
- Platforms
- ERPs and payment systems; email via module (connector unverified)
- Hosting
- Not documented
Trustpair
Best payee verificationOverall score: 3.9out of 10Best for: European finance teams paying many suppliers through SAP, Oracle or another ERP that need bank-account validation before every payment.
Trustpair validates vendor bank accounts in 190 countries, monitors vendor master data continuously and verifies payment files, blocking or flagging payments to unverified accounts. It integrates with ERPs, P2P and treasury systems through API, SFTP and 20+ native connectors, and offers up to $1M liability. Trustpair does not scan email. Basware, owned by Accel-KKR, completed its acquisition of the Paris-based company by October 2026; Trustpair operates independently.[13]
- Detects fraud inside email threads
- 1.0
- Acts before finance does
- 1.0
- Verifies the payee at payment
- 10.0
- Deployment effort
- 5.0
- Published price
- 3.0
- EU hosting documented
- 4.0
- Microsoft 365 and Google Workspace coverage
- 1.0
Pros
- Account validation in 190 countries
- Up to $1M liability
- SOC 1 Type 2, SOC 2 Type 2 and ISO 27001 (vendor)
Cons
- Does not see the fraudulent email
- ERP integration work
- No public prices; new owner in 2026
- Pricing
- Quote; packages with a fixed number of vendor evaluations per year
- Deployment
- ERP/P2P/TMS connectors via API or SFTP; access in 24 hours (vendor)
- Platforms
- SAP, Oracle and other ERPs, P2P and treasury systems
- Hosting
- Not documented
Eftsure
Overall score: 3.8out of 10Best for: Mid-market and enterprise AP teams that want independent payee verification with a financial guarantee.
Eftsure verifies payees and bank accounts independently, re-verifies them continuously and enforces segregation of duties across finance systems, stopping payments to unverified payees. The Eftsure Guarantee covers up to $1M for customers signed after 10 March 2025. It added the US firm Relish (September 2026) and is reported to have expanded into Europe by acquiring France’s Sis ID in 2025. No email scanning is documented.[16]
- Detects fraud inside email threads
- 1.0
- Acts before finance does
- 1.0
- Verifies the payee at payment
- 10.0
- Deployment effort
- 4.0
- Published price
- 3.0
- EU hosting documented
- 4.0
- Microsoft 365 and Google Workspace coverage
- 1.0
Pros
- $1M guarantee
- Continuous payee re-verification
- Reported EU presence through Sis ID
Cons
- Does not see the fraudulent email
- Weeks of onboarding
- No public prices
- Pricing
- On request; scales with annual spend and new vendors per month
- Deployment
- Finance-system integration; 1–3 weeks to anomaly verification (vendor)
- Platforms
- Finance, AP and ERP systems
- Hosting
- AWS, region not stated
What invoice fraud costs
How to choose invoice fraud protection
Two layers, two moments
Invoice fraud has two moments where it can be stopped. The first is when the request arrives: a supplier’s real mailbox, compromised, replies in an existing thread with “updated bank details”, or a lookalike domain sends an invoice that looks routine. The second is when the payment is made: the new account is entered in the ERP and a payment run is approved. Email security works at the first moment; payment-verification platforms such as Trustpair and Eftsure work at the second. Trustmi tries to span both.
| Layer | Stops | Misses | Tools |
|---|---|---|---|
| Email security (API or native) | The request itself, before anyone acts: hijacked threads, lookalike suppliers, payload-free payment redirects | Fraud that reaches finance by phone or a supplier portal | Sentaro, Defender for Office 365, Abnormal AI, Proofpoint, IRONSCALES |
| Payment verification (ERP) | Payments to bank accounts that do not belong to the supplier | The compromised conversation, and anything paid outside the integrated systems | Trustpair, Eftsure |
| Combined signals | Both, where integrations exist | Depends on connectors | Trustmi |
Why the email layer matters most for smaller teams
Payment platforms are strongest when there is an ERP, an AP team and thousands of suppliers. Most EU SMEs and mid-market firms pay a few hundred suppliers from an accounting system, and the person who reads the email is the person who changes the bank details. For them the request in the inbox is the control point. Invoice fraud usually carries no malicious link or attachment, so filters that look for payloads see nothing; what gives it away is context: a supplier who has never asked to change accounts, a reply that does not fit the thread, a domain registered last week.
Keep the process controls
No tool replaces a rule that bank-detail changes are confirmed by calling the supplier on a number already on file, never one from the email. Tools make the rule work by flagging the right emails so the check actually happens. Sentaro labels the verdict in the mailbox, which is where the person who would make the call sees it. Sentaro cannot inspect a phone call, so the call-back stays a human control.
Questions to ask every vendor
- How do you detect a changed bank account inside a real, existing supplier thread?
- Do you detect a compromised supplier mailbox, not just lookalike domains?
- Is the verdict visible to the recipient before they act, or only to the security team?
- How long before baselines work: days from existing history, or weeks of learning?
- Which mail platforms and ERPs do you connect to, and how long does that take?
- What does it cost for our headcount or payment volume, and where is our supplier correspondence processed?
Certification and compliance status
For your supplier-risk file, Sentaro’s own certification status, in Sentaro’s exact words.
- SOC 2
- In progressEvidence pack on request.
- ISO 27001
- In progress
- Google CASA
- Verified API integration
- DPA and subprocessor list
- Public
Frequently asked questions
What is the best invoice fraud protection?
Sentaro, for EU organizations on Microsoft 365 and Google Workspace. It detects changed bank details, hijacked supplier threads and lookalike supplier domains in the email itself and labels the verdict in the mailbox before finance acts, for $6 per protected account per month. Large AP departments should add a payee-verification platform such as Trustpair or Eftsure at the payment step.
What is invoice fraud?
Invoice fraud is when an organization is tricked into paying a fake invoice, or into sending a real payment to an attacker’s bank account. The most damaging form uses a supplier’s compromised or impersonated mailbox, often replying in a genuine thread with new bank details. The FBI counts the email-borne version as business email compromise.
Can email security stop invoice fraud?
It can stop most of it at the start, if it reads context rather than payloads. Invoice fraud rarely contains a link or attachment, so detection depends on relationship history, thread context and sender infrastructure. Sentaro is built for that case: it looks for suppliers that suddenly change banking details, injected replies and newly registered lookalike domains.
Do I need Trustpair or Eftsure if I have email security?
It depends on scale. If you pay thousands of suppliers through an ERP, payee verification adds a second, independent check before money moves. If a small finance team pays a few hundred suppliers, email-layer detection plus a call-back rule for bank-detail changes covers the main risk. The two layers do not overlap.
Does Microsoft Defender for Office 365 detect invoice fraud?
Partly. Plan 1 includes user and domain impersonation protection with mailbox intelligence. We found no dedicated vendor-email-compromise feature in Microsoft’s documentation, so fraud from a supplier’s real but compromised mailbox is the gap specialist tools such as Sentaro and Abnormal AI target. Sentaro runs alongside Defender rather than replacing it.
How does Sentaro detect a changed bank account in an email?
It compares the message with the history of the relationship and thread: who normally writes, how, from which infrastructure, and whether the supplier has ever asked to change payment details. Baselines come from existing mailbox history, so they work quickly. Intent signals such as payment redirects, secrecy and artificial deadlines are recognized in any language.
What changed in the payment-fraud market in 2026?
Consolidation. Basware, owned by Accel-KKR, acquired Trustpair, which continues to operate independently. Eftsure acquired the US firm Relish in September 2026, and is reported to have bought France’s Sis ID in 2025. Check post-acquisition pricing and data-processing terms before signing.
Sources and method
Sentaro publishes this list and ranks itself first; scores use the method above and public vendor documentation as of 21 October 2026. Product capabilities, prices and ownership change; check each vendor’s current documentation. Trademarks belong to their owners. Corrections: contact Sentaro.
- Sentaro: pricing
- Sentaro: Data Processing Agreement and subprocessor list
- Microsoft Learn: Why do I need Microsoft Defender for Office 365? (accessed 2026-10-18)
- Microsoft: Defender for Office 365 pricing (accessed 2026-10-18)
- Microsoft Learn: EU Data Boundary (accessed 2026-10-18)
- Abnormal AI: Inbound Email Security (accessed 2026-10-18)
- Proofpoint: Core Email Protection (accessed 2026-10-18)
- IRONSCALES: home page (accessed 2026-10-18)
- IRONSCALES: pricing (accessed 2026-10-18)
- Trustmi: home page, Email Fraud Detection, certifications (accessed 2026-10-21)
- Trustmi: platform (accessed 2026-10-21)
- Mimecast: Trustmi technology partner (accessed 2026-10-21)
- Trustpair: home page, capabilities, certifications (accessed 2026-10-21)
- Trustpair: pricing (accessed 2026-10-21)
- ITPro: Basware to acquire Trustpair (2026)
- Eftsure: pricing, guarantee and go-live timeline (accessed 2026-10-21)
- Eftsure: security (accessed 2026-10-21)
- Tech Coffee House: Eftsure acquires Relish (3 September 2026)
- FBI IC3 Internet Crime Report 2025 (as cited by Sentaro)
- Microsoft Tech Community: Defender for Office 365 Plan 1 rolling out to Microsoft 365 E3 (2026-06-17)
- Channel Life: Eftsure acquires Sis ID (2025, via search result)
- Abnormal AI: Subprocessors (updated 31 July 2026; accessed 2026-10-21)
- Proofpoint: Data privacy information sheet, Core Email Protection API (updated 24 July 2026; accessed 2026-10-21)
- IRONSCALES: List of current sub-processors (PDF, December 2024; accessed 2026-10-21)