Card processing · engineering partner
Credit card payment processing software,
engineered as a system you own.
TrustChange builds credit card payment processing software for EU PSPs, EMIs, neobanks, marketplaces and licensed operators. We engineer the checkout, the tokenisation vault, the 3-D Secure and PSD2 SCA flow, the acquirer router, the chargeback pipeline and the reconciliation ledger as bespoke code under your brand — not a SaaS licence with a per-transaction fee. You get payment processing software for credit card flows that your engineers can extend, your operators can run and your auditor can read.
- EU-based engineers
- PSD2 SCA in code
- 3DS2 exemption engine
- PCI DSS scope kept small
- GDPR-aware storage
What "card processing software" means here
Payment processing software for credit card flows, not a rented gateway
Most searches for credit card payment processing software surface hosted gateways with a licence, a per-transaction fee and a fixed feature set. We work the other way. TrustChange is a payment engineering partner: your brand, your acquirers, your rules, your code. What you buy is engineering — a card flow shaped around your markets, your risk appetite and your finance close.
Deciding whether to build or wrap what you have? Start with CTO advisory. The wider gateway view sits on payment gateway engineering.
Subsystems
Four subsystems inside every credit card payment processing software build
Card processing is not one service. It is four that must agree on every cent — from the moment a customer taps pay to the moment finance signs off the day. We build them together, on one plan, with one team accountable end to end.
-
01
Tokenisation & vault
Hosted fields, network tokens and vaulted card references so raw PAN data stays out of your systems and PCI DSS scope stays small.
- Hosted fields / iframe
- Network tokens
- Vault segregation
-
02
Authorisation & risk
3-D Secure 2 step-up, exemption logic, pre-auth risk checks and velocity rules that run before the charge is taken.
- 3DS2 with exemptions
- Velocity + BIN rules
- Sanctions screening
-
03
Capture, refund & chargeback
Deferred capture, partial refunds, chargeback intake and evidence pack assembly against the acquirer's timelines.
- Deferred + partial capture
- Refund idempotency
- Chargeback evidence packs
-
04
Settlement & reconciliation
Acquirer file ingestion, daily match against a double-entry ledger, exception queues and finance-ready close packs.
- Acquirer file adapters
- Break workflow with SLAs
- GL exports
Stack
What sits behind our payment processing software for credit card flows
Eight layers, one system. Every layer names an owner, a control and a piece of audit evidence — nothing is left implied under the "gateway" label.
Delivery patterns and evidence: how we deliver. Wider platform view: fintech infrastructure. Rule mapping: compliance engineering.
| Layer | What we build |
|---|---|
| Ingress & checkout | Hosted card fields, mobile SDKs, saved cards and one-click flows Raw PAN never touches your servers; only tokens do. |
| Tokenisation & vault | Vaulted card references and network tokens, per-tenant segregation Vault sits in a PCI DSS-scoped enclave; the rest of the platform stays out of scope. |
| Routing & orchestration | Rule-based routing across acquirers with cost-based selection and provider failover One rail down does not stop authorisations; retries are idempotent. |
| 3-D Secure & PSD2 SCA | 3DS2 authentication with exemption engine (TRA, low-value, allow-lists) and step-up flows Your advisers set the policy; the code applies it consistently and logs the reason. |
| Risk & fraud controls | Pre-auth velocity rules, BIN and country checks, sanctions screening, analyst case queue Every decision writes to the audit log with the rule version. |
| Ledger & reconciliation | Double-entry ledger, acquirer file adapters, daily match, break workflow Finance, ops and the auditor read the same source of truth. |
| Chargebacks & disputes | Intake feeds from acquirers, evidence assembly, deadline tracking, response submission Nothing is silently accepted; a case exists for every dispute. |
| Runtime & delivery | EU-hosted, CI/CD pipelines, observability, 24/7 on-call cover Your identity provider, your key custody, your data regions. |
Auth-to-settle path
From tap to settled funds
Every authorisation in the credit card payment processing software goes through the same gates before the ledger is written. Speed comes from tuning the pipeline, not from skipping a step or trusting the caller.
- 01
Checkout
Real time
Customer enters card in hosted fields; a token replaces the PAN before it reaches your systems.
- 02
Risk
Sub-second
Pre-auth rules run — velocity, BIN, country, screening — with the verdict stored against the request.
- 03
Auth & 3DS2
Sub-second
Router picks an acquirer; 3DS2 exemption or step-up applies; auth is requested and logged.
- 04
Capture
Same day
Funds are captured and posted to the double-entry ledger with an idempotent source id.
- 05
Settle & reconcile
T+1 to T+2
Acquirer files land, match rules run, payouts are issued and any breaks open cases.
- 06
Chargebacks
Days–weeks
Disputes are ingested, evidence packs assembled and responses submitted against acquirer deadlines.
Delivery
How we deliver a credit card payment processing software project
Five steps, in this order. Card work runs inside the product backlog — no separate compliance phase bolted on before launch, no big-bang release of an untested tokenisation path.
- 01
Scoping
Weeks 1–2
We map acquirers, markets, checkout surfaces, SCA policy and the audit expectations you must stand behind. Output: a scope, a control map and a costed plan.
- 02
Architecture
Weeks 3–4
Vault boundary, tokenisation path, router topology, 3DS2 exemption logic and ledger contracts written down first. PCI DSS scope shape is agreed here, not later.
- 03
Build
Two-week sprints
Checkout, vault, router, 3DS2, capture and reconciliation ship in slices. Each merge runs tests, static checks and a dependency scan.
- 04
Hardening
Before launch
Load work at target throughput, failure drills against acquirer outages, replay against historical files and a third-party pen-test window on the vault boundary.
- 05
Launch and run
Cutover + ongoing
Named engineers on 24/7 cover. Runbooks, dashboards, chargeback playbooks and the audit bundle are handed to your team on day one.
Engagement
Four ways to buy your card gateway build
Same engineers, same standard. Only the commercial shape changes.
-
Fixed-scope build
A defined card flow at a fixed price and date. Best when acquirers and markets are settled.
-
Dedicated team
A standing squad with a lead. Best for long roadmaps and new markets each quarter.
-
Staff augmentation
Senior engineers inside your team. Best when you already own the plan and need card depth.
-
CTO advisory
Architecture and buy-vs-build review before you commit. Best at the design stage.
Questions
FAQ: credit card payment processing software
Six answers up front on scope, off-the-shelf trade-offs, 3DS2, PCI DSS scope, acquirer integration and ongoing support. Bring the rest to the call.
What does credit card payment processing software cover in your builds?
We engineer the full card path — hosted-field checkout and tokenisation, 3-D Secure 2 with a PSD2 SCA exemption engine, acquirer routing with failover, deferred capture, refunds, chargeback intake and evidence assembly, settlement and daily reconciliation into a double-entry ledger. It ships as source code in your repositories, with the IP assigned to you. There is no per-transaction fee and no shared multi-tenant backend behind it.
How is your payment processing software for credit card different from an off-the-shelf gateway?
Off-the-shelf gateways bundle a generic flow with a licence and per-transaction fee, and expose only what their roadmap decides. TrustChange engineers the checkout, the router, the risk rules and the reconciliation against your actual acquirers, markets and audit expectations. A bespoke credit card payment processing software build takes longer up front, but you keep every rule and every code path, and you avoid the roadmap lock-in of a rented platform.
How do you handle 3-D Secure 2 and PSD2 SCA exemptions?
3DS2 is engineered as a first-class flow, not an afterthought — with an exemption engine covering TRA, low-value, whitelisting and out-of-scope transactions where policy allows. Your compliance and risk advisers set the policy; the code applies it consistently, logs every decision with a rule version and produces evidence a supervisor or acquirer risk team can read. Nothing about supervisor approvals or scheme-side certifications is claimed on your behalf.
How do you keep PCI DSS scope small on our side?
Raw PAN data never lands in your general application. Hosted fields, iframes and mobile SDKs pass cardholder data straight into a segregated tokenisation vault, so only tokens and network tokens circulate through the rest of the platform. That keeps most of your infrastructure out of PCI DSS scope. Formal PCI DSS certification is your organisation's responsibility; we engineer for readiness and produce the artefacts your QSA will ask for, but we do not claim your certification for you.
How does the card gateway integrate with acquirers, PSPs and the wider ledger?
Acquirer and PSP integrations are built as adapters that plug into one router — cost, currency and success-rate rules decide which rail runs each authorisation, and failover keeps traffic moving when a provider slows down. Everything settles into a double-entry ledger with a reconciliation engine that matches acquirer files against it daily and opens cases for breaks. GL exports and close packs feed your finance stack on the schedule you set.
Do you also run the card gateway 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 and an on-call handover we author together. Some keep us on as a dedicated development team or on staff augmentation for new-market and control roadmap work, or as CTO advisory on architectural calls.
Book a discovery call for credit card payment processing software
Bring the acquirer list, the market list, the SCA policy and the launch date. We come back with a control map, an architecture view and a costed plan for a card gateway you own end to end. No demo theatre.