The core banking system holds the authoritative record of every account and transaction. Choosing the right one shapes everything built on top of it, including how well you support customers in arrears.
This guide covers what a modern core must offer, how eight leading providers approach it, and where collections fits. Because the moment you choose a core is also the moment your collections architecture gets decided.
At the heart of any lending organisation is its core system of record. It is the single, authoritative source of truth for every customer account and transaction: it owns the ledger, calculates balances and applies payments. In financial services it is usually called the core banking system. For brevity, this guide calls it the core.
The quality of the core matters more for collections than almost anywhere else. Older cores process data in overnight batches, which is too slow and inflexible to support the tailored repayment arrangements customers in difficulty need. A modern core provides the foundation for better collections by offering:
Real-time data. A complete, up-to-the-minute view of a customer's situation supports more informed and empathetic conversations. Early, accurate signals are also what make pre-arrears intervention possible.
Product flexibility. The ability to design and launch new products quickly, such as tailored forbearance plans, to help customers in financial difficulty.
Easy integration. Modern cores are designed to connect with specialist systems. Collections is complex and highly regulated, so many core providers deliberately focus on the ledger and partner with specialists like Flexys for collections. The quality of a core's partnerships matters as much as its own features.
A modern, real-time core is the essential foundation, but it's only half the story. It provides the accurate, up-to-the-second data that a collections system needs to operate effectively. The real magic happens when you connect that core to specialised real-time collections software like ours. That's when you can create the intelligent, automated, and genuinely supportive customer journeys that improve outcomes for everyone.
Brian Smith, Chief Product Officer, Flexys
The core owns the loan ledger. It is the system of record for balances, transactions and payments, and nothing should duplicate that role.
Collections is a different job. Flexys holds the complete record of collections activity: every communication, arrangement, action and decision, with a full audit trail, in one system. It integrates with the core, which remains the source of balances and payments, and it does not replace it.
That separation is the point. The core does what only a core can do, and the collections engine handles the regulated, fast-moving work of supporting customers in arrears: automated workflows, agent tools and self-service, without a core replacement project attached. Lenders get better customer outcomes and a lower cost to collect from both systems doing their own job well.
If you are evaluating a new core, these eight providers cover most of the serious options for UK lenders and banks. Flexys partners with several of them and can integrate with all of them. Each profile covers what the provider does, how it supports collections, and how it works with Flexys.
Founded in Estonia in 2019, Tuum is a modular core banking system that lets lenders modernise piece by piece rather than replacing everything at once. Its configuration tools let business teams design and launch new repayment products quickly, without a complex IT project.
Working with Flexys: Tuum and Flexys announced a strategic partnership in July 2024, giving joint clients a pre-integrated route to modern collections.
UK-based and founded in 2016, SaaScada is a cloud-native core built on event sourcing: every change to an account is captured as an unchangeable event, creating a real-time audit trail and a rich stream of data. Flexys shares that architectural approach. Its Product Sequencer lets lenders configure and launch new forbearance products in minutes.
Working with Flexys: Flexys is an official partner in SaaScada's ecosystem.
Founded in London in 2014, Thought Machine's Vault Core is used by banks including Lloyds Banking Group, Standard Chartered, Intesa Sanpaolo and JPMorgan Chase. Its Universal Product Engine uses smart contracts to define the logic of any financial product, and its real-time design means data is instantly available for collections.
Working with Flexys: Flexys and Thought Machine announced a partnership in January 2024 to integrate Flexys with Vault Core.
Founded in 2011, Mambu pioneered composable banking: a core account-keeping engine with open APIs, designed for connecting specialist services around it. In September 2026 it launched Intelligent Core, bringing its core, payments and agentic AI products together. Mambu deliberately relies on specialist partners for collections, which makes integration straightforward.
Working with Flexys: Flexys has integrated with Mambu for clients using the system to manage collections.
Founded in 2016 by former Barclays CEO Antony Jenkins, 10x runs core infrastructure for Chase UK, Westpac and Old Mutual, and passed 10 million live accounts in 2026. Its meta core pairs a managed core with developer flexibility, built on an event-driven model that streams real-time data, an ideal foundation for modern collections.
Working with Flexys: Flexys can integrate with 10x to serve joint clients.
One of the largest names in banking technology, Temenos serves thousands of financial institutions worldwide with exceptional breadth of functionality and flexible deployment: on-premise, cloud or as a service. Its open architecture is designed for connecting external specialists.
Working with Flexys: the API-first design of Temenos makes a Flexys integration technically straightforward.
Founded in Brazil in 2016 and acquired by Visa in 2023, Pismo covers accounts, payments, card issuing and lending in one cloud-native system. It operates entirely in real time, with no batch processing, and its API-first design is intended to be extended with specialists for collections.
Working with Flexys: Pismo is a core banking partner, with an established relationship and a path for integrating to serve joint clients.
The financial software suite from Tata Consultancy Services, built for very large and complex core transformations. It runs an open marketplace of certified specialist providers for regulated functions like collections.
Working with Flexys: Flexys is an approved supplier on the TCS BaNCS Marketplace.
A simplified summary of the eight providers, to help you shortlist quickly. Every organisation's needs differ, so treat this as a starting point, not a verdict.
| Provider | Core architecture | Best suited to | Key differentiator | Collections approach |
|---|---|---|---|---|
| Tuum | Modular, API-first | Banks and fintechs modernising in stages | Progressive modernisation, business-user configuration | Pre-integrated with Flexys |
| SaaScada | Cloud-native, event-sourced | Digital banks and lenders wanting a data-rich core | Event sourcing and Product Sequencer | Real-time event data; Flexys partner |
| Thought Machine | Cloud-native, smart contracts | Tier 1 global banks | Universal Product Engine | Flexys integrates with Vault Core |
| Mambu | Composable, open APIs | Digital-first lenders and fintechs | Composable banking, now with Intelligent Core AI | Built to integrate specialist collections software |
| 10x Banking | Event-driven meta core | Large, established institutions | Managed core with developer flexibility | Real-time data streaming; Flexys integration available |
| Temenos | Broad suite, decoupled components | All tiers, global | Breadth of functionality and deployment choice | Open architecture for specialist integration |
| Pismo | Cloud-native microservices | Banks and fintechs wanting core, cards and payments in one | All-in-one system, Visa-owned | Designed for specialist collections integration |
| TCS BaNCS | Microservices, cloud-based | Large global institutions | End-to-end suite plus partner marketplace | Flexys approved on the TCS BaNCS Marketplace |
Looking across these providers, one trend stands out: choosing a core banking system today is also choosing its network of partners. That is especially true for a complex, regulated function like collections.
Most modern providers have concentrated on building powerful, flexible core engines rather than trying to do everything, leaving collections to specialists. That is not a weakness. It is a deliberate strategy: do the ledger brilliantly, and let clients connect the best software for everything else.
The consequence for lenders is direct. Your ability to run a modern, effective collections operation is tied to how well your core connects with a specialist provider. When evaluating a new core, look beyond its own feature list and assess the openness of its technology and the strength of its partner ecosystem.
The goal is a technology stack where a resilient, real-time core is matched with specialist software for every stage of the customer journey, so you can improve customer outcomes and reduce the cost to collect at the same time.
Choosing a new core is about more than just technology; it's about building an ecosystem that puts the customer first. This is especially true in collections, where the right partnership can transform a challenging process into an opportunity to build trust and deliver positive outcomes for everyone.
James Hill, CEO, Flexys
If you'd like a second opinion on what technology stack would work best for your collections operation, we're happy to share what we've seen work.
Talk to a collections specialistIt is the system that holds the authoritative record of every customer account and transaction. It owns the ledger, calculates balances and applies payments. Everything else in a lender's technology stack, from origination to collections, reads from it and writes back to it. In financial services it is usually shortened to "the core".
The core owns the ledger and is the source of truth for balances and payments. A collections system like Flexys holds the complete record of collections activity: communications, arrangements, actions, decisions and the audit trail. The two integrate. The core stays the system of record for the money; the collections system runs and evidences everything done to support a customer in arrears.
Rarely in any depth. Most modern cores deliberately focus on the ledger and rely on specialist partners for complex, regulated functions like collections. That is why the openness of a core's APIs and the strength of its partner ecosystem matter as much as its native features.
Three things above all: real-time data rather than overnight batch processing, the flexibility to launch new products such as forbearance plans quickly, and open, well-documented integration. Assess the partner ecosystem alongside the feature list, because your collections capability will be shaped by how well the core connects to specialist software.