The companies building the UK’s next generation of fintech, accounting, and payments products all hit the same wall. Getting clean, reliable bank data into a product is harder than it should be, and the cost of getting it wrong is significant.
The way financial software companies access bank data is changing. For years, the default was manual: ask clients to upload a bank statement, wait for a CSV file, or chase a payslip.
It worked well enough when the product was simple. It stops working the moment a business needs automation, real-time decisioning, or any kind of operational scale.
Open Banking changes that. In the UK, it gives regulated providers the right to access bank account data, with user consent, and to initiate payments directly from bank accounts.
For scaleups building accounting tools, fintech platforms, payroll systems, or marketplace products, it is the infrastructure layer that makes real-time financial workflows possible.
That shift is already well underway.
1 in 5 UK consumers and small businesses are now active Open Banking users, up from 1 in 17 in 2021.
Source: Open Banking Limited, Impact Report 7, May 2025
The infrastructure that once served a narrow regulatory mandate has become a mainstream part of how UK businesses and consumers interact with their finances.
But the gap between what Open Banking promises and what most scaleups experience in practice is significant.
To understand how scaleups actually experience Open Banking infrastructure, Finexer spoke with founders, product leaders, and engineering teams building fintech, accounting, and SaaS platforms across the UK.
Across those conversations, the same operational challenges surfaced repeatedly.
What scaleups actually run into
Conversations with UK fintech and SaaS companies building on Open Banking consistently surface the same set of challenges.
- Inconsistent bank behaviour. Every UK bank implements its authentication flow differently. What works in a test environment often behaves unexpectedly in production: extra screens, different redirect logic, and Strong Customer Authentication steps that vary between mobile and desktop.
- Data quality. Raw transaction data arrives as reference strings such as AMZNMKTP UK, SQ*, or 3569TFL. These are not usable by an accounting platform or a affordability risk model without further processing. Without reliable enrichment, the raw data has limited practical value.
- Pricing unpredictability. Many accounting SaaS and tax tools serve customers on modest monthly plans. Per-user or per-connection pricing can deteriorate unit economics quickly. Several teams report unexpected invoice increases when dormant users reconnect accounts.
- Integration time. Consent flows, re-authentication logic, API-based event handling, and multi-account management are complex to build properly. On a venture-backed timeline, a lengthy integration can mean missing a funding milestone or losing a product window.
“If integrating Open Banking adds months to our launch, we would rather ship without it than slip the roadmap.”
Fintech founder, speaking during customer discovery conversation
What Finexer is
Finexer is an FCA-authorised Open Banking infrastructure provider. It gives UK platforms API access to verified bank data across 99% of UK banks, including business accounts and challenger banks.
It also enables account-to-account payments without platforms needing to build and maintain the underlying bank connections independently.
The scale of the underlying ecosystem gives context to why that infrastructure matters.
The UK Open Banking ecosystem recorded 24 billion successful API calls in 2025, up 27% on 2024. Payment initiation API calls grew 53% year-on-year.
Source: Open Banking Limited, January 2026
For platforms building on Open Banking, that volume signals an ecosystem that has crossed from early adoption into operational scale.
What Finexer does and does not provide
Finexer does not provide accounting software, tax filing, lending decisions, or payroll management.
It provides the connectivity and data layer that sits underneath those products. Platforms retain full control of product logic and user experience. Finexer handles what sits below the application layer.
Most scaleups do not want to become specialists in PSD2 consent models or the integration behaviour of dozens of UK bank APIs. They want to build their core product.
Finexer is designed to manage that infrastructure complexity so that product teams can direct their focus toward the application rather than the connectivity plumbing underneath it.
How it works in practice
The core of what Finexer provides covers three areas: real-time bank data access, transaction enrichment, and payment initiation infrastructure.
Bank data access
Finexer
Platforms access live transaction feeds via Finexer’s API across major UK banks, including up to seven years of historical data where available.
That depth matters for tax platforms building annual returns and affordability tools running longer-horizon credit models. Many providers limit historical access below what production use cases require.
Transaction enrichment
The enrichment layer is where raw bank data becomes usable.
Finexer runs transaction categorisation against a database of over 100 million merchants, with categorisation accuracy above 95% and processing latency under 100 milliseconds.
Merchant identification, income and expense classification, and recurring transaction detection are all available within the same API response as the raw feed, rather than as a separate overnight processing job.
Payment initiation
For payroll-adjacent and marketplace platforms, the payment initiation infrastructure supports bulk payouts across multiple recipients, with failure handling and reconciliation reporting for finance teams.
This is a different operational requirement from the single-payment consumer flows that most Open Banking APIs were originally designed to support.
Account-to-account payments are scaling rapidly alongside demand for that infrastructure.
31 million Open Banking payments were made in March 2025 alone, equivalent to 7.9% of all UK Faster Payments, with 70% year-on-year volume growth.
Source: Open Banking Limited, Impact Report 7, May 2025
For marketplace and payroll platforms evaluating Open Banking as a payment rail, that growth rate reinforces the case for adoption.
“Paying one person through Open Banking is straightforward. Paying 500 workers every week, tracking failures, and reconciling it all is where the complexity begins.”
Marketplace operations lead, describing bulk payout challenges during Open Banking infrastructure evaluation
Integration speed and cost
Two questions come up consistently when scaleups evaluate Open Banking providers: how long it takes to go live, and what it will cost as the platform scales.
Integration speed
Finexer is built to support deployment timelines that run two to three times faster than typical market integrations.
Hands-on onboarding support is structured to help product and engineering teams progress efficiently. This support model is specifically designed for teams without dedicated payments expertise, which covers most companies entering this space for the first time.
Pricing
Finexer uses a usage-based pricing model. Costs track actual API consumption rather than committed volumes or per-user connections.
For platforms in early growth, where active users and API usage vary from month to month, this means infrastructure costs scale more proportionally with revenue.
Platforms switching from per-user or committed-volume contracts to usage-based API pricing have reported significant reductions in their Open Banking infrastructure costs. The saving depends heavily on the legacy pricing structure and usage pattern, but for early-stage platforms that were paying for capacity they were not using, the difference can be substantial
Compliance and the regulatory question
Regulatory uncertainty is a consistent concern for UK scaleups adopting Open Banking.
Accounting platforms question whether aggregating client transaction data and surfacing spending insights requires AISP registration. Marketplace platforms with pooled fund mechanics are uncertain how their Open Banking use cases interact with e-money regulation.
Finexer holds FCA authorisation covering both account information and payment initiation services.
Platforms operating under an agent model with an authorised provider can reduce certain compliance complexities in their Open Banking integration. However, each platform retains its own regulatory obligations depending on its specific operating model. Independent legal advice remains important for any platform assessing its own regulatory position.
Having a clearly structured regulatory framework matters commercially. It surfaces in investor due diligence, enterprise procurement reviews, and sales processes where buyers ask how data is being accessed and under what regulatory authority.
Where this is heading
The UK remains one of the most advanced Open Banking markets globally, but adoption among scaleups has been uneven.
The primary barrier has not been lack of interest but the practical difficulty of building reliably on the infrastructure as it currently exists.
The demand signal from small businesses is particularly relevant for the platforms this article describes.
Open Banking penetration among UK small businesses has consistently run ahead of consumer adoption, with 18% of small businesses using Open Banking services as of early 2024, compared to 13% of consumers.
Source: Open Banking Limited, Impact Report, January 2024
For accounting, payroll, and ERP platforms whose end customers are small businesses, that means the audience they serve is already operating in an Open Banking context, whether or not the platform has caught up.
That is changing more broadly. Data enrichment capabilities are maturing. Bank coverage is broadening.
Infrastructure providers designed around the needs of product teams, rather than large financial institutions, are making faster and more cost-efficient integrations more achievable.
The scaleups treating Open Banking as core infrastructure, at the same level of strategic importance as their database or identity stack, are building products that depend on real-time financial data in ways that were not practical a few years ago.
Those treating it as a supplementary feature tend to encounter the operational complexity later, when it is more disruptive to address.
The question for UK scaleups is not whether to build on Open Banking. It is how to select the infrastructure that makes the build viable.
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