Payment Processing Solutions Built Around Your Business
Your business shouldn’t have to change the way it operates to accommodate the limitations of a payment processing plugin or standard ecommerce platform.
Nexus Software Systems develops custom payment gateway integrations that connect payment processors to websites, ecommerce platforms, and proprietary business applications. We work directly with payment processor APIs to build payment processing functionality that fits your software, business requirements, and transaction workflows.
Whether you need to integrate Stripe, PayPal, Authorize.Net, or another payment processor, we can develop the custom functionality needed to make payment processing work within your existing systems.
From integrating credit card processing into a custom web application to connecting payment transactions with an established business management system, we develop solutions that go beyond standard payment gateway installations.
Have a payment processing requirement that standard software can’t accommodate? Let’s discuss a custom solution.
Custom Payment Gateway Integration Services
Payment gateway integration can involve considerably more than connecting a checkout form to a payment processor. Businesses often need custom transaction handling, communication between multiple software systems, automated billing, and payment functionality that works within existing applications.
We provide custom development for a range of payment processing requirements.
Payment Gateway API Integration
Integrate payment processors directly into websites and applications using their available APIs. Develop custom functionality for transaction authorization, payment capture, refunds, and other payment operations.
Custom Payment Processing
Build payment functionality into proprietary business software, web applications, customer portals, and other systems that need to accept or process payments.
Ecommerce Payment Integration
Connect ecommerce websites and custom shopping cart applications to payment gateways. Develop checkout and transaction processing functionality around your ecommerce requirements.
Recurring Billing & Subscription Payments
Implement recurring payment functionality for subscriptions, memberships, installment payments, and automated billing arrangements supported by your payment provider.
Payment Tokenization
Integrate gateway-managed payment tokens and customer payment profiles to support saved payment methods and subsequent transactions without unnecessarily storing sensitive card information.
Legacy Payment Integration Upgrades
Modernize existing payment integrations, replace outdated gateway connections, and upgrade older applications to work with current payment processor APIs.
Multiple Payment Processor Integration
Integrate multiple payment providers into a single application, allowing businesses to support different merchant accounts, payment methods, or processing requirements.
Payment System Integration & Automation
Connect payment processing with existing customer databases, order management systems, invoicing applications, and other business software to streamline transaction-related operations.
Payment Processor API Integration
We have experience developing custom integrations with multiple payment processing providers, including Stripe, PayPal, and Authorize.Net.
Payment processing API integration
Online payments and custom software integration
Payment gateway and transaction processing integration
We also have experience with other payment processing services and can work with additional providers that offer suitable API access and integration capabilities.
Our approach is to work with the payment processor’s available functionality to develop an integration that meets your application requirements.
This includes evaluating the provider’s API, understanding the available transaction operations, and determining how payment processing should interact with your existing software.
You aren’t limited to the payment functionality available through a standard plugin. Custom API development gives us the flexibility to build around your particular application and business processes.
Integrating Payment Processing Into Existing Business Software
Payment gateway integration isn’t limited to ecommerce websites.
Many businesses operate custom software that manages important aspects of their operations but doesn’t have the payment processing capabilities they need. Replacing that software simply to accommodate online payments may be unnecessary.
Instead, payment processing can often be integrated directly into the existing application.
Nexus Software Systems develops custom integrations that allow business software to communicate with payment processors and incorporate transaction processing into established workflows.
Some examples include:
Custom Business Applications
Add payment processing capabilities to proprietary applications used to manage customers, orders, services, and everyday business operations.
Customer Portals
Allow customers to make payments, pay outstanding balances, and manage supported payment methods through an existing online account.
Invoicing & Accounting Systems
Connect payment processors to invoicing applications and related business systems to automate payment status updates and transaction-related workflows.
CRM & ERP Applications
Integrate payment-related functionality with customer relationship management and enterprise resource planning systems, connecting transactions with customer and operational records.
Membership & Subscription Platforms
Incorporate recurring payment functionality into membership applications, subscription services, and other systems that manage ongoing customer relationships.
Order Management Systems
Connect payment transactions with order processing, payment confirmation, customer notifications, and fulfillment workflows.
The objective is to make payment processing a natural part of your existing software rather than introducing another disconnected system that requires manual management.
Beyond Basic Payment Processing: Custom API Development
A successful payment integration needs to account for the entire transaction lifecycle, not just the initial payment submission.
Depending on the payment processor and application requirements, custom integrations can incorporate a variety of transaction operations and supporting functionality.
Transaction authorization and capture
Support payment authorization and capture workflows, including applications where authorization and final payment capture occur at different stages of an order or service transaction.
Refunds and voids
Integrate transaction reversal and refund functionality into business applications, allowing authorized users or automated workflows to manage payment adjustments.
Customer payment profiles
Work with payment processor customer profiles and tokenized payment methods to support returning customers and subsequent transactions.
Recurring transaction processing
Integrate subscription billing and automated recurring payment functionality using the capabilities provided by the selected payment processor.
Webhooks and transaction notifications
Process payment processor notifications to keep your application informed about transaction events, payment status changes, refunds, and other asynchronous activities.
Transaction reconciliation
Connect payment transaction information with internal application records to help businesses track payments and reconcile transaction activity.
Error handling and duplicate transaction protection
Develop appropriate transaction validation, error handling, and duplicate submission safeguards to help maintain reliable payment processing workflows.
Custom payment workflows
Build application-specific transaction logic that connects payment processing with order management, customer accounts, service delivery, and other business operations.
Not every payment processor supports every capability, and implementation details vary by provider. We evaluate the available APIs and integration methods when determining the best approach for each project.
How Custom Payment Gateway Integration Works
A payment gateway integration establishes communication between your application and the payment processor. The exact architecture depends on the selected provider, application, and payment methods.
A typical integration may follow this general process:
Payment Initiated
A customer initiates a payment through your website or application.
API Communication
Your application securely communicates with the payment processor using its API or supported integration method.
Transaction Processing
The payment provider processes the transaction and returns the appropriate response.
Application Updates
Your application handles the transaction result, updates relevant records, and communicates the payment status.
Additional processing may occur through webhooks and other asynchronous notifications, allowing your application to respond to subsequent transaction events.
The integration can also connect payment activity to other software components, such as customer accounts, order management, invoicing, and reporting systems.
Custom Payment Integration vs. Standard Payment Plugins
Standard payment plugins are useful when a business operates on a supported ecommerce platform and its requirements fit the functionality provided by the plugin.
However, businesses with proprietary software, specialized transaction requirements, or multiple interconnected systems may need a different approach.
Custom payment integration is especially valuable when your business needs payment processing to work with software that is already central to its operations.
Rather than changing your business processes to accommodate a plugin, we can develop an integration around your existing application and the functionality offered by your payment provider.
Secure Payment Processing & Integration
Security is an essential consideration when developing payment gateway integrations.
Payment processing involves sensitive financial information and communications between applications and payment providers. Integrations must be designed with appropriate security controls and the requirements of the selected payment processor in mind.
Depending on the integration, development considerations include:
- Secure API authentication and credential management.
- Encrypted communications using HTTPS.
- Payment tokenization and gateway-managed payment methods.
- Server-side transaction processing.
- Validation of transaction responses.
- Webhook signature verification and secure event handling.
- Appropriate handling of transaction errors and duplicate submissions.
- Protection of sensitive payment information.
- Secure logging and transaction monitoring.
- Consideration of applicable PCI DSS requirements.
Where supported, payment processor-hosted checkout experiences and tokenization can help reduce the exposure of sensitive payment credentials within your application.
PCI DSS responsibilities vary depending on the payment architecture, provider, and how cardholder data is handled. Integrations should be designed with the appropriate compliance responsibilities in mind.
Our Experience With Custom Payment Gateway Integration
Payment gateway integration is often part of a larger software development project.
Businesses may need to upgrade an existing ecommerce application, replace an outdated payment connection, or extend software that already handles important business functions.
Nexus Software Systems has experience developing custom software and working directly with payment processor APIs to implement payment processing functionality.
Our experience includes working with established payment providers such as Stripe, PayPal, and Authorize.Net, as well as integrating payment processing into existing applications.
Ecommerce Website Upgrade & Payment Gateway Integration
One example of our work involved upgrading an existing ecommerce website to incorporate payment gateway API functionality.
The project demonstrates our ability to work with existing ecommerce software and extend its capabilities through custom development rather than relying exclusively on standard payment integrations.
The work involved payment gateway integration and improvements to payment-related functionality within the existing ecommerce environment.
View the Ecommerce Website Upgrade & Payment Gateway Integration Case Study →
This experience is particularly relevant to businesses that already have an established website or application and need to expand or modernize its payment processing capabilities.
Why Choose Nexus Software Systems for Payment Gateway Integration?
Payment processing is too important to treat as an isolated website feature. It needs to work reliably with the rest of your software and business operations.
Nexus Software Systems brings custom software development experience to payment gateway integration projects.
Custom Software Development
We develop application-specific solutions rather than relying exclusively on prebuilt payment plugins and extensions.
Payment API Experience
We have experience working directly with payment processor APIs, including Stripe, PayPal, and Authorize.Net.
Existing System Integration
We can integrate payment processing into existing websites, ecommerce platforms, and proprietary business applications.
Beyond Ecommerce
Our capabilities extend to custom business software, customer portals, invoicing systems, and other applications requiring payment functionality.
Legacy Application Upgrades
We can work with existing applications to upgrade, replace, or extend payment processing functionality.
Business-Focused Solutions
We consider how payment processing fits into your overall business operations, not just how to make a transaction work.
Frequently Asked Questions
What is custom payment gateway integration?
Custom payment gateway integration is the process of connecting a payment processor to a website, ecommerce platform, or software application using its available APIs and integration methods.
Unlike standard plugins, custom integrations can be developed around the specific requirements of your application, including transaction processing, recurring payments, refunds, customer payment profiles, and connections to other business systems.
Can you integrate Stripe, PayPal, and Authorize.Net?
Yes. We have experience developing custom integrations with Stripe, PayPal, Authorize.Net, and other payment processing providers.
We work with their available APIs to implement payment functionality within websites, ecommerce applications, and custom business software.
Can you integrate payment processing into our existing software?
Yes. You don’t necessarily need a new website or application to add payment processing.
We can evaluate your existing software and determine how to integrate a payment processor into its current architecture. This may involve developing a new API connection, adding payment functionality, or upgrading an existing integration.
Can you develop a payment integration for custom business software?
Yes. We develop custom integrations that allow proprietary applications and business systems to communicate with payment processors.
Examples include customer portals, invoicing applications, business management software, order management systems, and other custom web applications.
Can you integrate multiple payment processors?
Yes. Depending on the application requirements and available provider APIs, we can integrate multiple payment processors into a single website or application.
This may be useful for businesses that have multiple merchant accounts, different processing requirements, or a need to support alternative payment providers.
Can you implement recurring payments and subscription billing?
Yes. We can develop integrations for recurring payment functionality supported by the selected payment processor.
Depending on the requirements, this can include subscription billing, automated transactions, customer payment profiles, and payment status updates.
Can you integrate saved payment methods and tokenization?
Yes. We can work with payment processor tokenization services and customer payment profiles to support saved payment methods and subsequent transactions.
This allows applications to work with provider-managed payment tokens instead of unnecessarily storing raw credit card information.
Can you upgrade or replace an existing payment gateway integration?
Yes. We can evaluate existing payment integrations and develop replacement or upgraded functionality.
This can be useful when a payment processor discontinues an older API, an existing integration becomes incompatible with current requirements, or a business wants to transition to another payment provider.
Do you only provide payment gateway integration for ecommerce websites?
No. Although ecommerce is an important application of payment gateway integration, our services also include payment processing for custom business software, proprietary applications, customer portals, and other systems.
If your application needs to communicate with a payment processor, we can evaluate the available integration options.
How much does custom payment gateway integration cost?
The cost depends on the selected payment processor, application architecture, integration complexity, and required functionality.
A relatively straightforward API integration will generally involve less development than a solution involving multiple payment processors, recurring billing, customer payment profiles, and connections to other business applications.
We evaluate each project individually and provide an estimate based on its requirements.
Let’s Discuss Your Payment Gateway Integration Project
Whether you’re looking to integrate Stripe, PayPal, Authorize.Net, or another payment processor, Nexus Software Systems can help develop a solution around your application and business requirements.
We work with payment processor APIs and custom software to connect payment processing with websites, ecommerce platforms, and existing business applications.
You may be looking to:
- Add credit card processing to an existing application.
- Develop custom payment functionality for proprietary software.
- Connect an ecommerce website to a payment gateway.
- Replace or upgrade an outdated payment integration.
- Automate recurring payments or subscription billing.
- Connect payment transactions with other business systems.
Whatever your requirements, we’d welcome the opportunity to discuss your project.
Tell us what you’re trying to accomplish, what software you’re currently using, and which payment processor you’re considering.