Open Banking Platform Development: A Buyer’s Guide for UK Fintechs & Lenders

Introduction

UK open banking stopped being a fintech experiment sometime in 2025. By December that year, user connections had reached 16.5 million (up from 12.1 million a year earlier), payments hit 351 million across the year — a 57% jump — and API calls climbed to 24 billion, according to Open Banking Limited’s year-end review. If you’re a bank, lender, PropTech platform, or SaaS founder weighing whether to commission open banking platform development, the market has already answered the “should we?” question. What’s left is the harder one: how do you build it without triggering an FCA enforcement letter six months post-launch?

This guide is written for buyers, not for open banking evangelists. It walks through what an Open Banking platform actually needs to do, where AISP and PISP integrations fit, how consent and security obligations work under the UK’s post-Brexit rulebook, and what a realistic build plan and use case list look like — all specific to the Open-Banking lane (UK), which now runs on its own regulatory track separate from the EU’s PSD2/PSD3 evolution.

What Open Banking enables

Open Banking is the regulated framework that lets customers give licensed third parties secure, API-based access to their bank account data and payment rails — with explicit, revocable consent. In the UK, it was born out of a 2016 Competition and Markets Authority investigation that led to the 2017 Order requiring the nine largest banks (CMA9) to open their APIs, and it has since evolved well beyond compliance theatre. 

Practically, an Open Banking platform enables three things:

1. 1. Data access — real-time visibility into a customer’s balances, transactions, and account details, standardised via the Open Banking API specification.
   2. Payment initiation — moving money directly from a customer’s bank account, bypassing card rails entirely.
   3. Identity and affordability signals — using transaction history for KYC, credit risk scoring, and income verification, which is increasingly why lenders and challenger banks commission this work in the first place.

The scale numbers back this up: as of March 2025 there were 13.3 million active open banking users in the UK, up 40% year-on-year, and for the first time consumer adoption caught up with small business adoption, per the OBL Impact Report 7. This differs from connection figures such as the 16.5 million reported for 2025 because connections are counted per bank brand and are not deduplicated across users.  One in five UK consumers and small businesses is now an active user — up from 1 in 17 in March 2021. That’s the addressable market a platform like this taps into.

AISP / PISP integration

Two licence types sit at the centre of any UK Open Banking build, and getting the distinction right shapes your entire architecture.

Account Information Service Provider (AISP)

An AISP reads account data — balances, transaction history, standing orders — from a customer’s bank (the ASPSP, or account servicing payment service provider) with consent. This is the licence you need for affordability checks, personal finance dashboards, accounting reconciliation tools, or credit-risk models.

Payment Initiation Service Provider (PISP)

A PISP triggers a payment directly from the customer’s account. This is what powers pay-by-bank checkouts, sweeping between accounts, and recurring bill collection — without card fees or chargebacks.

Both require direct integration with each ASPSP’s dedicated API interface, and in practice most platforms integrate through an aggregator (TrueLayer, Plaid, Yapily, or similar) rather than connecting to all regulated UK banks one by one. That decision — build a direct multi-bank integration layer versus route through an aggregator — is usually the single biggest cost and timeline variable in an Open Banking build, and it’s one we scope explicitly during discovery on every engagement.

One structural shift buyers should plan around: Variable Recurring Payments (VRPs). Sweeping Variable Recurring Payments (VRPs)—which move money between a customer’s own accounts—grew 98% year on year in 2025. Meanwhile, the UK Payments Initiative (UKPI), backed by 31 firms, launched its commercial (non-sweeping) VRP scheme on 2 June 2026. Wave 1 covers regulated financial services, utilities, and local and central government payments, while broader Wave 2 use cases, including general e-commerce, are expected in H2 2026. If your use case involves recurring collections (subscriptions, rent, loan repayments), design your PISP integration with commercial VRP support in mind now rather than retrofitting it later.

Consent & security (FCA / PSD2)

Here’s a distinction that trips up a lot of buyers: the UK is no longer under PSD2. PSD2 was implemented into UK law via the Payment Services Regulations 2017 (PSRs 2017), and post-Brexit, the UK has been diverging from the EU’s rulebook on its own track — most recently as the EU moves toward PSD3/PSR while the UK’s own reforms run through the FCA and the Payment Systems Regulator (PSR) directly, per Pinsent Masons’ analysis of the diverging SCA regimes. Any platform built for “PSD2 compliance” without accounting for UK-specific PSRs 2017 requirements and FCA SCA-RTS updates is building against the wrong rulebook.

Three compliance layers matter for a platform commissioned in 2026:

• • Strong Customer Authentication (SCA). The FCA has already carved out its own exemptions — notably Article 10A, which lets account servicing banks skip repeat SCA prompts when a regulated AISP is accessing account information, rather than forcing re-authentication every 90 days per bank. Your consent flow needs to be built around the FCA’s current SCA-RTS, not the EU’s.
  • Safeguarding. The FCA’s Policy Statement PS25/12 materially tightens safeguarding requirements for payment institutions and e-money institutions, with new rules on daily segregation monitoring and reconciliation that took effect on 7 May 2026. The FCA’s updated safeguarding guidance sets out the requirements for protecting customer funds, including reconciliation and reporting obligations. If your platform (or your AISP/PISP partner) holds or transmits customer funds, this is now a build requirement, not a policy afterthought.
  • Consent architecture. Every data pull and payment initiation needs a clear, time-boxed, revocable consent record — not a blanket “connect your bank” toggle. Regulators and banks alike are increasingly scrutinising consent UX as much as the underlying API security.

This is also where the regulatory landscape is actively shifting: JROC (the Joint Regulatory Oversight Committee, jointly run by the FCA and PSR) wound down after the government’s National Payments Vision named the FCA as lead regulator for the sector’s future entity, per Global Regulation Tomorrow. Build with FCA and PSR guidance as your primary sources, and treat industry commentary as secondary. 

Account aggregation & payments

Once AISP/PISP access is wired up, the platform layer is where the actual product value gets built. Two functional blocks dominate most builds:

Account aggregation pulls balances and transactions from multiple banks into a single view — the foundation for personal finance apps, SME cash-flow dashboards, and multi-bank reconciliation tools. Real-time API performance now matters commercially, not just technically: average unweighted API availability across UK banks reached 99.22% in October 2025, with response times averaging 331 milliseconds, though individual banks vary sharply — AIB Group UK led at 100ms while the slowest bank recorded over 700ms, per Payment Expert. Design your aggregation layer to degrade gracefully against slow ASPSPs rather than assuming uniform performance.

Payments cover single domestic payments (one-off, immediate) and the VRP categories described above. In 2025, single domestic payments grew 52% and sweeping VRPs nearly doubled. If your platform serves SMEs specifically, it’s worth considering the funding constraints that continue to shape the market. CFIT estimates the UK SME funding gap at £22 billion, while 94% of firms referred to a second lender are rejected again. This creates a strong case for Open Banking-powered alternative credit assessment, where transaction-level financial data can support more informed lending decisions. We’ve built exactly this kind of product before — our alternate credit assessment platform for a fintech client used transaction-level Open Banking data in place of traditional credit bureau scores. 

Building compliant Open Banking apps

Whether you commission it in-house or outsource it, a compliant open banking platform development roadmap follows a predictable sequence:

1. 1. Licence and partner decision. Decide early whether you’ll seek your own FCA AISP/PISP authorisation or operate as an agent under an existing authorised provider (406 firms currently operate as agents rather than direct licence holders, per OBL). Direct authorisation gives you control; agent status gets you to market faster.
   2. Aggregator vs. direct-bank integration. Map your target ASPSPs and pick an integration approach based on coverage needs and budget — this is usually a 4-8 week discovery exercise on its own.
   3. Consent and SCA UX design. Build consent screens and re-authentication flows around current FCA SCA-RTS exemptions, not generic PSD2 templates.
   4. Safeguarding architecture. If funds are held or transmitted, build segregation and daily reconciliation into the core ledger design now — PS25/12 compliance is now mandatory under the rules that took effect on 7 May 2026 .
   5. Security and audit trail. Every consent grant, data pull, and payment initiation needs an immutable, timestamped audit log — both for FCA reporting and for dispute resolution.
   6. Staged rollout. Launch with a narrow ASPSP set and a single use case (e.g., affordability checks only), then expand to payments and additional banks once the consent and audit layers are proven in production.

This is close in spirit to how we approached document verification with a GDPR-compliant, signed audit trail for a UK client — the regulatory logic (consent, immutability, audit-first design) carries across from data protection into payments.

Use cases

Open Banking platforms in active UK production today fall into a handful of proven categories:

• • Alternative credit scoring — using real transaction history instead of (or alongside) credit bureau data, particularly valuable given how many SMEs are rejected by traditional lenders after a first decline.
  • Financial inclusion and community finance — rebuilding legacy lending infrastructure around Open Banking data to serve underbanked segments, an area we’ve worked in directly through a community finance platform rebuild for financial inclusion in the UK.
  • Pay-by-bank checkout — replacing or supplementing card payments at checkout via PISP-initiated transfers, cutting interchange costs.
  • Subscription and recurring billing — using sweeping and commercial VRPs to collect recurring payments without card expiry or chargeback friction.
  • SME cash-flow and accounting tools — account aggregation feeding directly into bookkeeping, forecasting, or invoice-financing products.
  • Affordability and income verification — for lenders, landlords, and insurers who need real income data rather than self-reported figures.

Given how fast VRP volume and commercial rollout are moving — 351 million Open Banking payments in 2025 alone, with the UKPI commercial VRP scheme now live since 2 June 2026 — the use cases that look niche today, such as recurring bill collection via bank transfer, are likely to become increasingly mainstream as Wave 2 expands commercial VRPs into broader use cases, including general e-commerce, in H2 2026. 

The bottom line for buyers

Open Banking in the UK has crossed the line from “emerging” to “expected.” With 16.5 million active connections, 351 million payments, and Wave 1 of the UKPI commercial VRP scheme now live, the question for most buyers isn’t whether to build on this rail — it’s whether the build is done right the first time. The platforms that struggle post-launch are almost always the ones that treated AISP/PISP integration as a checkbox and consent/SCA design as an afterthought, rather than building the two together from day one.

If you’re scoping an open banking platform development project, the decisions that matter most are made before a single line of code is written: which licence route you’ll take, whether you integrate direct or through an aggregator, and how you’ll comply with the FCA’s PS25/12 safeguarding requirements, which took effect on 7 May 2026, if your platform touches customer funds at all. Get those right, and the rest — aggregation, payments, use-case expansion — becomes a matter of execution rather than regulatory risk.

Frequently Asked Questions