Integrated payments · engineering partner
Integrated payment processing software,
engineered as a stack you own.
TrustChange builds integrated payment processing software for EU-facing ISVs, POS platforms, PSPs and EMIs. We engineer the embedded checkout, the SDKs, the merchant onboarding, the router, the ledger and the reconciliation as bespoke code under your brand — not a SaaS licence with a per-transaction fee. You get an integrated payments stack your product team can extend, your merchants can self-serve on and your auditor can read.
- EU-based engineers
- PSD2-aware delivery
- PCI DSS scope kept small
- GDPR-aware storage
What "integrated" means here
Integrated software vendors payment processing — without the platform lock-in
Most searches for integrated software vendors payment processing surface platforms that put their brand on your checkout and take a rev-share. We work the other way. TrustChange engineers a bespoke integrated payments stack under your brand — the embed, the SDKs, the router, the ledger, the merchant portal — with the code assigned to you and the merchant relationship kept on your side of the wire.
Adjacent detail: payment processing software development, credit card payment processing software and payment ledger & reconciliation development. For open-banking rails see open banking API integration.
Product surface
Three surfaces in every POS software with integrated payment processing engagement
An integrated payments stack is not one component. It is the embed on the merchant's software, the merchant-facing tooling and the internal router. We ship all three together, on one architecture, with one team accountable end to end.
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01
Embedded checkout & SDKs
Drop-in checkout components, hosted fields and native SDKs so your POS, SaaS or vertical software takes payments inside its own flow — no redirect off-brand.
- Hosted fields (PCI-safe)
- Web + iOS + Android SDKs
- Card-present + card-not-present
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02
Merchant onboarding & console
KYB, underwriting handover and a merchant portal where your customers see transfers, refunds, disputes and payouts in one place, under your brand.
- KYB & underwriting flow
- Merchant portal per tenant
- Payouts & statements
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03
Router, ledger & reconciliation
One router picks the working path across acquirers and PSPs, a double-entry ledger records every movement, reconciliation matches against files daily.
- Rule-based routing & failover
- Double-entry ledger
- Aged break workflow
Stack
What sits behind integrated payment processing software
Eight layers, one system. Every layer names an owner, a control and a piece of audit evidence — nothing is left implied under the "integrated" label.
Rule mapping: compliance engineering. On-chain payout legs: wallet and custody engineering and crypto payment gateway development.
| Layer | What we build |
|---|---|
| Embed surface | Hosted fields, drop-in components, native mobile SDKs and terminal integrations Card data stays out of your systems; PCI DSS scope stays small. |
| Router & orchestration | Rule-based routing across acquirers and PSPs with health checks and failover New partners plug in as adapters, not code changes across the platform. |
| Risk & fraud controls | Velocity rules, device fingerprinting hooks and vendor screening before capture Rules are versioned; analysts see the reason attached to every decision. |
| Ledger & postings | Double-entry ledger with idempotent postings and per-merchant sub-ledgers Retries never mint money twice; every posting carries a source id. |
| Reconciliation | Adapters into acquirer files, PSP webhooks and bank statements with tolerance rules Aged break queues, SLAs and re-run per case, not per batch. |
| Merchant tooling | Onboarding, KYB, portal, statements, disputes and refunds under your brand Support stops living in your inbox; merchants self-serve on the portal. |
| Compliance controls | PSD2/SCA logic, sanctions and AML screening hooks, GDPR-aware storage Every decision writes to the audit log with rule and operator context. |
| Runtime & delivery | EU-hosted, CI/CD pipelines, observability, 24/7 on-call cover Your identity provider, your data regions, your access rules. |
Payment path
From tap on the POS to a settled merchant payout
Every payment in the integrated stack goes through the same gates before it is captured. Speed comes from tuning the pipeline, not from skipping a step or trusting the caller.
- 01
Trigger
Real time
A customer taps pay on the POS, in the app or on the SaaS checkout; the request is signed with the merchant context.
- 02
Risk
Sub-second
Velocity, device and vendor screening run before capture; the verdict is stored on the request.
- 03
Route
Sub-second
The router picks the working acquirer / PSP path and applies retry and failover rules.
- 04
Authorise & capture
Provider-bound
SCA exemption logic and step-up flows run per PSD2; funds are captured to the ledger.
- 05
Reconcile
T+1
Provider files are matched line by line; breaks land in the aged case queue.
- 06
Payout & report
T+1 to T+2
Merchants are paid out; reports go to finance, the merchant portal and the auditor bundle.
Delivery
How we deliver an integrated payment processing software project
Five steps, in this order. Regulated payment work runs inside the product backlog — no separate compliance phase bolted on before launch, no big-bang release of an untested integrated stack.
- 01
Scoping
Weeks 1–2
We map merchant segments, embed surfaces (POS, mobile, web), providers, licence context and the risk you must stand behind. Output: a scope, a control map and a costed plan.
- 02
Architecture
Weeks 3–4
SDK surface, router topology, merchant model, ledger schema and reconciliation adapters written down first. Regulatory constraints shape the design.
- 03
Build
Two-week sprints
Embed, SDKs, router, ledger and merchant portal ship in slices. Each merge runs tests, static checks and a dependency scan.
- 04
Hardening
Before cut-over
Load work, failure drills, PCI DSS-scope review preparation and a third-party pen-test window. Cut-over is rehearsed with your ops team.
- 05
Launch and run
Cut-over + ongoing
Named engineers on 24/7 cover. Runbooks, dashboards, SDK release playbooks and the audit bundle are handed to your team on day one.
Engagement
Four ways to buy your integrated payment processing build
Same engineers, same standard. Only the commercial shape changes.
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Fixed-scope build
A defined integrated payments stack at a fixed price and date. Best when embed surfaces and providers are settled.
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Dedicated team
A standing squad with a lead. Best for long roadmaps and new merchant segments each quarter.
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Staff augmentation
Senior engineers inside your team. Best when you already own the plan and need integrated-payments depth.
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CTO advisory
Architecture and buy-vs-build review before you commit. Best at the design stage.
Questions
FAQ: integrated payment processing software
Six answers up front on scope, ISV/POS/PSP audiences, PCI DSS scope, platform lock-in trade-offs, PSD2/AML/GDPR and ongoing support. Bring the rest to the call.
What does integrated payment processing software from TrustChange cover?
We engineer a bespoke, client-owned integrated payment processing stack end to end: the embedded checkout and SDKs, the merchant onboarding and portal, the router and ledger, the reconciliation and the compliance controls. It ships as source code in your repositories, with the IP assigned to you. There is no per-transaction fee, no shared multi-tenant backend and no vendor gate between your software and your merchants.
Who typically buys this — ISVs, POS platforms, PSPs or someone else?
Two audiences. First, independent software vendors and POS platforms building POS software with integrated payment processing — payments inside their own checkout, not a redirect off-brand. Second, PSPs, acquirers and EMIs that want to become integrated software vendors payment processing partners for a vertical (retail, hospitality, marketplaces, healthcare) with a branded embed and a merchant portal on top of their existing rails.
How does POS software with integrated payment processing keep PCI DSS scope small?
The embed uses hosted fields and native SDKs so raw card data never touches your servers or terminals — it lands directly with the acquirer or PSP. Your systems only ever handle network tokens, order metadata and posting references. That keeps your PCI DSS scope to SAQ-A or equivalent for the software layer, with the terminals handled by their own certified path. We ship the code and the evidence; your QSA does the assessment.
How is your build different from becoming an ISV on someone else's platform?
Joining a platform means their brand, their portal, their roadmap and per-transaction rev-share. Bespoke integrated payment processing software puts your brand on the embed, your merchants on your portal, your routing rules in your admin console, and your data in your regions. A bespoke build takes longer up front, but you keep the merchant relationship and every line of code, and you avoid the roadmap lock-in that comes with an off-the-shelf ISV platform.
How are PSD2, SCA, AML and GDPR engineered into the integrated stack?
TrustChange is an engineering partner, not a law firm — your advisers set the policy, we ship the controls and the evidence. That means PSD2-aware SCA exemption and step-up logic in the checkout, sanctions and AML screening hooks before capture, PSP-side tokenisation to keep PCI DSS scope small, and GDPR-aware storage with data mapping and retention rules per merchant class. Nothing about licences, authorisations or supervisor approvals is claimed on your behalf.
Do you also run the integrated platform after launch, or hand it over?
Both are on the table. Most clients start with named TrustChange engineers on 24/7 cover during the first months while their own team ramps up, then take the platform in-house with runbooks, dashboards, SDK release playbooks and the audit bundle. Some keep us on as a dedicated development team or on staff augmentation for new-rail, terminal and merchant-tooling roadmap work.
Book a discovery call for integrated payment processing software
Bring the embed surfaces (POS, mobile, web), the acquirers and PSPs you want to route across, the merchant segments and the launch date. We come back with a control map, an architecture view and a costed plan. No demo theatre.