Open Banking API Integration Services

There are three distinct regulatory roles. The Account Information Service Provider (AISP) reads account data under consent, and a Payment Initiation Service Provider (PISP) executes transfers from the customer’s account.

The Account Servicing Payment Service Provider (ASPSP) is the bank that holds the funds and provides both capabilities. There is a different licensing process for each category and certain technical requirements; thus, selecting incorrectly at the first stage implies a total redevelopment of the consent management procedure.

Start with multi-bank connectivity aggregators. If a product should be widely covered by many banks and countries, open banking API providers based on aggregators become a faster solution than others. At SPD Technology, we utilize this approach if needed. For Mogami, within a ten-year cooperation in the field of personal finance, we introduced a third-party data aggregation solution into production. Custom development becomes justified if the regulatory layer is crucial but not the coverage.

Payments made through the open banking API are transferred directly from bank account to bank account, without the participation of card networks. The user agrees to make a payment and is redirected to their bank, where they complete Strong Customer Authentication, and the transfer is made after their return. Since there is no interchange fee, merchants with small margins continuously consider this rail. Our payment software development services build these authorization pathways.

Open banking API security rests on four layers. Strong Customer Authentication uses genuine multi-factor elements. OAuth 2.0 and OpenID Connect handle authorization, QWAC/QSEAL certificates carry organizational identity, and TLS with AES protects data in transit and at rest. Missing one and a passing sandbox test still become a failed audit. Our guide to fintech app security breaks down how the layers hold.

Buy for breadth, build for depth. Platforms and open banking API providers win on coverage and speed to first integration. That is the right trade for simple consumer applications with a standard compliance surface. Custom open banking API solutions win when you need deep core-banking synchronization, ownership of the regulatory layer, or predictable economics at volume.

Custom engineering requires an upfront capital investment, typically ranging from $150,000 to over $300,000, for architecture, API gateways, and initial data scopes. Connectivity aggregators instead operate on predictable per-transaction or monthly user licenses.

Choosing a vendor platform lowers your initial development expense but shifts the economic burden to operational costs that scale with your expanding user base. Custom infrastructure converts those variable vendor fees into fixed architectural assets, so cost stops tracking transaction volume once it crosses enterprise thresholds.

This work is narrowly focused on the API integration layer. AISP and PISP role architecture, consent mechanisms, certificate lifecycle, and per-bank sandbox approvals make up the scope. Core ledger management, card issuing, and consumer-facing mobile UX sit outside it. The engagement is scoped per role and per bank, while a complete neobank build is a program with its own roadmap.

Three variables set the schedule, and code volume is not among them. Licensing first: the FCA decides within 3 months on a complete application and 12 months at the outside, with AISP and PISP authorizations commonly taking 6 to 12 months. Certification second: PSD2’s RTS makes every ASPSP open a testing facility 6 months before launch and gives TPPs only 3 months’ notice of interface changes. Bank count multiplies both. Price those three before putting a date on an open banking API integration.

A central normalization layer plus configuration-driven regional rules. Bank-specific and regime-specific differences resolve into one internal contract. Rules that vary by jurisdiction live in configuration rather than in branching code paths. When a jurisdiction updates its framework, engineers make a targeted configuration change instead of rewriting the core engine. Our guide to payment processing compliance, including PSD2, details how isolated compliance logic limits risk.