Sponsor Bank Liability in BaaS: How FinTechs Can Avoid Shared AML Enforcement Risk

Banking-as-a-Service (BaaS) has enabled a wave of FinTech innovation. Non-bank companies can offer payments, accounts, cards, and lending products by partnering with licensed sponsor banks, allowing them to scale quickly without holding a banking charter themselves. That model has driven rapid growth across embedded finance, neobanking, and platform-based financial services.

Regulators, however, are increasingly focused on the risks this model creates. In 2025, the Office of the Comptroller of the Currency (OCC) fined multiple sponsor banks for failing to ensure that their FinTech partners maintained adequate Bank Secrecy Act (BSA) and AML programs. At the same time, FinCEN guidance reinforced a critical point: operating under a bank’s charter does not remove compliance responsibility from FinTechs. Instead, it creates shared liability.

This article explores how sponsor bank liability in FinTech is evolving, why BaaS AML compliance is now a shared responsibility, and what FinTechs must do to avoid enforcement risk.

{{snippets-guide}}

How the BaaS model creates shared risk

The BaaS model is built on division of roles. The sponsor bank provides the regulated infrastructure, including access to payment rails and the ability to hold deposits. The FinTech manages the customer experience, onboarding, product design, and often large parts of the operational workflow.

From a commercial perspective, this division is efficient. From a compliance perspective, it creates ambiguity.

Who is responsible for:

• Customer due diligence and onboarding?
• Sanctions screening?
• Transaction monitoring?
• Suspicious activity reporting?
• Ongoing customer risk assessment?

In practice, responsibilities are often split through contractual agreements. But regulators are less interested in contractual language and more focused on outcomes. If a FinTech introduces high-risk customers or fails to monitor activity properly, the sponsor bank is exposed. If the bank fails to oversee its partner effectively, it is also exposed.

This creates a model where risk is inherently shared.

Regulatory direction: OCC enforcement and FinCEN guidance

Recent regulatory actions have made this shared responsibility explicit.

The OCC’s enforcement actions against sponsor banks  highlighted failures in third-party risk management, particularly where banks did not adequately oversee the AML controls of their FinTech partners. These cases emphasized that banks cannot outsource compliance responsibility simply by partnering with a FinTech.

FinCEN has reinforced this position by clarifying that FinTechs operating under a bank’s charter are still expected to maintain effective AML controls. Even where the bank retains formal responsibility for certain regulatory filings, the FinTech’s role in customer interaction and transaction flow means it is directly implicated in compliance outcomes.

The implication is clear. BaaS is not a regulatory shield. It is a shared compliance environment.

Why sponsor bank liability is increasing

Several factors are driving increased scrutiny of banking as a service sanctions and AML risk.

Rapid growth of embedded finance

BaaS has expanded quickly, often outpacing the development of robust compliance frameworks. As FinTechs scale, the volume and diversity of transactions increase, making weaknesses in AML controls more visible.

Fragmented control environments

In many BaaS setups, compliance processes are split across multiple systems and teams. The FinTech may handle onboarding, while the bank manages transaction monitoring, or vice versa.

This fragmentation creates gaps where risk can go undetected.

High-risk customer segments

Some FinTechs target underserved or higher-risk customer segments, including cross-border users, gig economy participants, or small businesses with limited documentation. These segments require stronger AML controls, not weaker ones.

Increased regulatory expectations

Regulators now expect sponsor banks to implement rigorous third-party oversight, including ongoing monitoring of FinTech partners’ compliance programs. At the same time, they expect FinTechs to operate as if they were directly regulated entities.

The practical impact for FinTechs

For FinTechs, the shift toward shared liability changes the compliance equation.

It is no longer sufficient to rely on the sponsor bank’s controls. FinTechs must be able to demonstrate that:

• They understand their AML and sanctions risk exposure
• They have implemented appropriate controls
• They can detect and escalate suspicious activity
• They maintain audit trails and documentation

Failure to do so can lead to indirect enforcement through the sponsor bank relationship, loss of that relationship, or direct regulatory scrutiny.

Where BaaS compliance programs often fail

Understanding common failure points is critical.

Over-reliance on the sponsor bank

Some FinTechs assume that the bank will handle core compliance functions. This can lead to gaps in onboarding, screening, or monitoring.

Inconsistent customer due diligence

If onboarding processes are not aligned between the FinTech and the bank, risk profiles may be incomplete or inconsistent.

Weak sanctions screening integration

Sanctions screening may be performed at onboarding but not integrated into ongoing monitoring or transaction flows.

Poor data sharing and visibility

Fragmented systems can prevent the bank and FinTech from having a unified view of customer activity.

Lack of auditability

Without clear records of decisions and processes, it becomes difficult to demonstrate compliance during audits or investigations.

Building a defensible BaaS AML compliance program

To address BaaS AML compliance requirements, FinTechs need to treat compliance as core infrastructure rather than a dependency.

Clearly defined responsibility models

FinTechs and sponsor banks must establish clear, documented responsibilities for each part of the AML lifecycle.

This includes:

• Who performs onboarding checks
• Who conducts sanctions screening
• Who monitors transactions
• Who files suspicious activity reports

Clarity reduces ambiguity and ensures accountability.

Integrated screening and monitoring

Sanctions screening, PEP checks, and adverse media monitoring should be integrated into both onboarding and ongoing operations.

This ensures that risk is assessed continuously, not just at the point of entry.

Real-time data sharing

Effective compliance requires both parties to have access to relevant data.

This may involve:

• Shared dashboards or reporting systems
• API-based data exchange
• Standardized data formats

The goal is to eliminate blind spots.

Risk-based customer segmentation

Not all customers present the same level of risk.

FinTechs should segment customers based on factors such as geography, transaction behavior, and product usage, applying enhanced controls where necessary.

Continuous monitoring and escalation workflows

Transaction monitoring systems should be capable of detecting unusual patterns and triggering escalation workflows.

These workflows must be clearly defined and consistently applied.

Strong audit trails and documentation

Every compliance decision should be traceable.

This includes:

• Screening results
• Risk assessments
• Escalation actions
• Final decisions

Auditability is essential for regulatory defensibility.

The role of technology in managing shared liability

Technology plays a central role in managing sponsor bank liability in FinTech environments.

Modern compliance systems can:

• Perform real-time sanctions and PEP screening
• Reduce false positives through intelligent matching
• Enable continuous monitoring of customer activity
• Provide centralized case management
• Generate audit-ready records

For BaaS models, integration is particularly important. Compliance tools must connect seamlessly with both FinTech and bank systems to ensure consistency and visibility.

{{snippets-case}}

The evolving relationship between FinTechs and sponsor banks

As regulatory expectations increase, the relationship between FinTechs and sponsor banks is changing.

Banks are becoming more selective in choosing partners and more demanding in their oversight. They may require:

• Detailed compliance documentation
• Regular reporting and audits
• Demonstration of control effectiveness
• Alignment with bank-level risk standards

For FinTechs, this means compliance capability is becoming a competitive factor. Firms with strong AML and sanctions programs are more attractive partners and better positioned to scale.

Conclusion

The BaaS model has unlocked significant innovation, but it has also created a shared compliance environment where responsibility cannot be outsourced.

Regulatory actions by the OCC and guidance from FinCEN make it clear that sponsor bank liability in FinTech is real and increasing. FinTechs operating under a bank’s charter are expected to maintain robust AML and sanctions controls, not rely on the bank as a safety net.

To operate safely and scale sustainably, FinTechs must build compliance infrastructure that is integrated, auditable, and aligned with regulatory expectations. That means clear responsibility models, real-time screening, continuous monitoring, and strong data sharing.

In a BaaS world, compliance is no longer a boundary between organizations. It is a shared system, and both sides are accountable for how well it works.

sanctions.io is a highly reliable and cost-effective solution for real-time screening. AI-powered and with an enterprise-grade API with 99.99% uptime are reasons why customers globally trust us with their compliance efforts and sanctions screening needs.

To learn more about how our sanctions, PEP, and criminal watchlist screening service can support your organisation's compliance program: Book a free Discovery Call.

We also encourage you to take advantage of our free 7-day trial to get started with your sanctions and AML screening (no credit card is required).

‍