What is the SWIFT Integration Layer (SIL) and why it matters to financial institutions

What is the SWIFT Integration Layer (SIL)?

The SWIFT Integration Layer (SIL) is middleware developed by SWIFT to simplify how financial institutions connect their internal applications to SWIFTNet, the global financial messaging network. It acts as an abstraction layer between an organisation’s core systems and the SWIFT network, shielding internal platforms from the underlying messaging protocols and connectivity requirements.

In practical terms, SIL allows payment engines, treasury platforms, trade processing systems, and reconciliation tools to exchange messages with SWIFTNet without having to implement SWIFT-specific standards directly. This integration layer centralizes transformation, routing, and protocol management. It empowers institutions across banking, securities, and FinTech to secure connectivity through a structured, controlled framework.

What Does SIL Do?

At an operational level, SIL performs the heavy lifting required to make reliable connectivity to SWIFTNet possible. It is positioned between internal systems and the network, absorbing the complexity of SWIFT standards, communication protocols, and security requirements so that upstream applications can focus on business logic rather than network mechanics. Whether the message originates from a payments engine, a trade settlement platform, or a treasury system, SIL standardises how it is prepared, transmitted, and tracked.

Its core functions include:

• Message Transformation & Routing: Translates internal data formats into SWIFT-compliant FIN, ISO 20022 (MX), or FileAct messages and routes them to the correct counterparty.
  
• Protocol Handling: Manages InterAct, FileAct, and FIN communication protocols so internal applications do not need to implement them directly.
  
• Queuing & Orchestration: Buffers, prioritises, and sequences messages between applications and the network to ensure orderly processing.
  
• Security & Compliance: Embeds SWIFT security policies, authentication mechanisms, and non-repudiation controls.
  
• Monitoring & Logging: Provides operational dashboards, message tracking, and structured error handling for production environments.
  
  

What are SIL’s Capabilities?

SIL was designed to reduce the complexity of integrating multiple internal systems with SWIFTNet in a standardised and controlled way. Its capabilities reflect that objective and focus on reliability, interoperability, and compliance within the SWIFT ecosystem.

• Multi-protocol support (FIN, FileAct, InterAct): Enables institutions to handle different SWIFT messaging channels through a single integration layer.
  
• Built-in translation between legacy formats and ISO 20022: Supports coexistence between MT (ISO 15022) and MX (ISO 20022) messaging standards.
  
• Connection pooling and load balancing for high throughput: Maintains performance and availability under production-scale message volumes.
  
• Integration via APIs, MQ, file drops, or adapters: Connects to upstream systems using multiple enterprise integration patterns.
  
• Audit and reconciliation tools for regulatory compliance: Provides traceability and control to meet internal governance and external regulatory requirements.
  
  

The SIL sunset - What Institutions Need to Know

In 2024, SWIFT announced the end of support for the SWIFT Integration Layer (SIL) and the related Alliance Access Integration Platform (IPLA). The decision was driven by the sunsetting of Red Hat Fuse, a core technology dependency underpinning both platforms. As a result, financial institutions must complete their migration before 2026.

Continuing to operate SIL beyond that point introduces operational, security, and compliance risk, particularly as vendor support and security updates cease.

The sunset reflects a broader strategic shift by SWIFT toward cloud-native, API-first connectivity models. At the same time, the MT to MX transition under ISO 20022, with the effective end of MT payments messaging in November 2025, is reshaping message standards across the network.

Although the MT migration and the SIL sunset are separate decisions, they converge at the architecture level. Addressing them together provides an opportunity to consolidate integration layers, simplify infrastructure, and modernise connectivity rather than treating the change as a standalone compliance exercise.

Gresham’s Competitive Positioning

Financial institutions require reliable and secure connectivity to SWIFT. At the same time, they also need to integrate multiple external networks, custodians, counterparties, and APIs. The choice is between a SWIFT-only middleware vs. a universal integration platform.

We've broken down a comparison between both tools:

Ultimately, SIL solves the SWIFT connectivity challenge, but Gresham's Connect Cloud expands the model to unify all data flows across systems, protocols, and counterparties, under one single and governed integration framework.

Summary

• SIL = middleware for SWIFT connectivity, protocol handling, and compliance.
• Connect Cloud = enterprise-wide integration and connectivity hub where SWIFT is just one of many supported channels.
  

If a firm only needs “how do I plug my apps into SWIFTNet?”, SIL is an adequate solution.

If a firm needs “how do I normalize and orchestrate data across SWIFT, custodians, APIs, and multiple asset classes?”, Gresham's Connect Cloud is the stronger and more flexible solution.

Connect with a member of our team today to learn more about how we can adapt our tools to your institution's needs.

Frequently Asked Questions

Is SWIFT SIL still supported?

No. SWIFT announced the end of support for SIL in 2024. Financial institutions are required to migrate before 2026, and continued use beyond that point introduces operational, security, and compliance risk due to the withdrawal of vendor support and updates.

What is the difference between SIL and IPLA?

SIL (SWIFT Integration Layer) manages message transformation, routing, and protocol handling between internal applications and SWIFTNet. IPLA (Alliance Access Integration Platform) is a related integration framework within the SWIFT stack. Both platforms depend on Red Hat Fuse and are being sunset on the same timeline.

What is a SWIFT code?

A SWIFT code, also known as a BIC (Bank Identifier Code), is an 8 or 11-character identifier that uniquely identifies a financial institution. It is used to route messages across the SWIFT network. A SWIFT code identifies the institution, whereas SIL provides the integration layer that enables systems to exchange messages with the network.

Who uses SWIFT SIL?

Any organisation connecting internal systems to SWIFTNet may use SIL. This includes commercial and investment banks, custodians, broker-dealers, asset managers, insurers, and FinTech firms. It has historically been common in mid-to-large institutions that require structured message transformation without building custom protocol handling from scratch, and in software or IT teams responsible for maintaining financial connectivity infrastructure.

What is the ISO 20022 migration and how does it relate to SIL?

ISO 20022 is the global financial messaging standard replacing legacy MT (ISO 15022) formats. November 2025 marked the effective end of MT for payments messaging on SWIFT. The MT transition and the SIL sunset are separate initiatives, but both require institutions to reassess their messaging architecture. This makes it practical to address them as part of the same modernisation programme.