As your business grows, you might be grappling with the challenges legacy systems pose during the billing process. These systems have served you the best in the past, but with technological advancements, you must adopt modern, feature-rich invoicing solutions.

To overcome efficiency barriers, choosing a billing software that seamlessly integrates with your existing legacy systems becomes essential.

This blog post discusses the top 11 billing software that can integrate with your legacy system to deliver optimal solutions. These billing solutions come with robust integration capabilities, which will help harmonize your financial operations and eliminate manual data entry.

Before we move to the recommendations, let’s look at the challenges you might face while using legacy systems for invoicing.

Challenges with Legacy Systems

Businesses face many difficulties in their billing operations because of legacy systems. A few challenges are discussed here and might encourage you to think about cutting-edge billing solutions for better processes and long-term readiness.

1. Outdated Technology

The use of out-of-date hardware and software by legacy billing systems is one of their major drawbacks. These systems need more adaptability and capacity to manage modern billing procedures effectively.

2. Limited Integration

Legacy systems are frequently abandoned because they were not created to integrate smoothly with other modern software or third-party applications. This restriction may make it difficult to share data and force manual data entry, which could result in inefficiencies and mistakes.

3. Inefficient Processes

Legacy billing systems may include difficult-to-understand procedures that require much human work. This inefficiency may cause billing cycles to drag out, delay invoice creation, and affect the organization’s general financial management.

4. Data Security Risks

Older legacy systems might not have strong security safeguards, which leaves them open to cyberattacks and data breaches. Sensitive financial information may be exposed due to insufficient data protection procedures, which could result in losses in money and reputational harm.

5. Incompatible Reporting

Producing thorough financial reports in real-time using legacy systems can be challenging. A lack of customizable reporting options may hamper examining data and decision-making processes.

6. Dependency on Expertise 

As staff familiar with legacy systems retire or take on new positions, specialized knowledge of these systems may become hard to acquire. The systems may become challenging to manage due to dependency.

7. High Maintenance Costs 

Maintaining and sustaining legacy systems tend to rise as they age. Maintenance costs may be higher for businesses than investing in more advanced billing options with superior long-term returns.

So, to eliminate all these challenges, let’s discover the tools that can integrate with your legacy systems and help your business succeed and grow.

Key Features to Look for in Integrated Billing Software

Top 11 Billing Software for Legacy System Integration

1. Invoicera

Invoicera logo1Invoicera is a billing software offering customizable invoices, time tracking, and multiple payment gateway support for efficient invoicing.


Customizable Invoices: Invoicera allows users to create personalized invoices with their branding and logo, enhancing the professional image.

Time and Expense Tracking: Users can track billable hours and expenses, making it easier to generate accurate invoices.

Multiple Payment Gateways: Invoicera supports various payment gateways for smooth and secure transactions.

Recurring Billing: Automate recurring billing cycles for subscription-based businesses.

ERP/CRM Integration: It helps reduce errors and saves time.

Integration Capabilities:

API Integration: Invoicera offers robust API integration, allowing seamless communication and data exchange with legacy systems and other applications.

CRM Integration: This integration allows you to sync all your customer data in one place. Any updates made in your CRM, such as contact details, leads, or customer notes, are instantly reflected in Invoicera and vice versa.

ERP Integration: ERP integrations help to minimize compliance risk and reduce cost.

2. Freshbooks

freshbook logoFreshbooks provides online invoicing, expense tracking, and a client portal for accessible communication and payment processing.


Online Payments: Freshbooks allows clients to pay invoices online through various payment methods.

Expense Tracking: Users can track expenses and attach receipts to invoices for transparent billing.

Time Tracking: Automated time tracking helps bill accurately for hourly-based projects.

Client Portal: Freshbooks offers a client portal for easy communication and access to invoices and estimates.

Integration Capabilities:

API Integration: Freshbooks provides APIs that enable smooth integration with legacy systems, ensuring real-time data synchronization and seamless communication.

Project Management Tools Integration: Freshbooks can integrate with project management tools, ensuring billing information is up-to-date and accurate.

3. Quickbooks

Quickbook logoQuickbooks offers advanced reporting, inventory management, and tax compliance features for comprehensive financial management.


Advanced Reporting: Quickbooks provides detailed financial reports for better insights into business performance.

Inventory Management: Track and manage inventory levels, making product invoicing more efficient.

Tax Management: Automate tax calculations and stay compliant with tax regulations.

Bank Reconciliation: Quickbooks facilitates easy reconciliation of bank transactions with invoiced amounts.

Integration Capabilities:

API Integration: Quickbooks offers REST APIs and SDKs, facilitating integration with legacy systems and other applications for efficient data transfer and synchronization.

E-commerce Platform Integration: Quickbooks can integrate with e-commerce platforms, streamlining the flow of order and payment data.

4. Finly

Finly logoFinly automates billing, offers approval workflows, and manages expenses and vendor information for streamlined financial processes.


Automated Billing: Finly automates the billing process, reducing manual errors and saving time.

Approval Workflows: Set up multi-level approval workflows for invoices to ensure accuracy and control.

Expense Management: Track and manage expenses, allowing for proper reimbursement and billing.

Vendor Management: Maintain vendor records and handle vendor-specific billing requirements.

Integration Capabilities:

API Integration: Finly offers API integration capabilities to connect with legacy systems and other business software, enabling automated data exchange and streamlined processes.

ERP Software Integration: Finly can integrate with Enterprise Resource Planning (ERP) software, ensuring financial data is accurately synchronized.

5. CloudBlue

CloudBlue logoCloudBlue specializes in subscription billing, partner management, and usage tracking for flexible pricing options.


Subscription Billing: CloudBlue specializes in subscription-based billing with various pricing models.

Partner Management: Manage billing processes for partners and resellers with ease.

Usage Tracking: Track usage-based billing for flexible pricing options.

Revenue Recognition: Automate revenue recognition and comply with accounting standards.

Integration Capabilities:

API Integration: CloudBlue provides robust APIs to integrate legacy systems and other business applications, ensuring smooth communication and data transfer.

CRM and Sales Tool Integration: CloudBlue can integrate with CRM and sales tools, streamlining billing processes for sales-generated revenue.

6. Tally Solutions

tallyTally Solutions provides comprehensive accounting and financial management, inventory tracking, and multilingual support.


Accounting and Financial Management: Tally Solutions provides comprehensive accounting and financial features.

Tax Compliance: Ensure adherence to tax regulations with automated tax calculation and reporting.

Inventory Tracking: Manage inventory and generate invoices for products with ease.

Multilingual Support: Tally supports multiple languages, facilitating global operations.

Integration Capabilities:

API Integration: Tally Solutions provides APIs for seamless integration with legacy systems and other software, ensuring smooth data exchange and synchronization.

Point of Sale (POS) System Integration: Tally can integrate with POS systems to streamline retail billing and inventory management.

7. Tipalti

tipalti logoTipalti offers global payment management, supplier onboarding, and payment reconciliation for efficient financial operations.


Global Payment Management: Tipalti streamlines cross-border payments with multi-currency support.

Supplier Onboarding: Automate supplier onboarding and maintain accurate vendor records.

Tax Compliance: Ensure tax compliance with Tipalti’s tax form collection and validation.

Payment Reconciliation: Simplify payment reconciliation with automated processes.

Integration Capabilities:

API Integration: Tipalti offers API integration capabilities, facilitating seamless connectivity with legacy systems and ERP software.

ERP Software Integration: Tipalti can integrate with ERP systems for accurate financial data transfer.

8. Xero

Xero logoXero provides bank connections, project tracking, and payroll management for enhanced financial control.


Bank Connections: Xero syncs with bank accounts for easy reconciliation and tracking of transactions.

Project Tracking: Track project-related expenses and bill clients accordingly.

Payroll Management: Xero provides payroll functionality for streamlined employee billing.

Expense Claims: Simplify expense claim management for employees and contractors.

Integration Capabilities:

API Integration: Xero offers a range of APIs for integration with legacy systems and other business tools, ensuring smooth data exchange and real-time synchronization.

CRM Software Integration: Xero can integrate with CRM software, enhancing customer information visibility during invoicing.

9. Wave

wave logoWave offers free invoicing, accounting and bookkeeping, and receipt scanning for small businesses.


Free Invoicing: Wave provides free invoicing tools with essential features for small businesses.

Accounting and Bookkeeping: Wave offers basic accounting features for expense tracking and reporting.

Receipt Scanning: Scan and attach receipts to invoices for better record-keeping.

Collaboration: Collaborate with team members or accountants on financial matters.

Integration Capabilities:

API Integration: Wave provides APIs for integrating with legacy systems, ensuring smooth data exchange and communication.

Payment Gateway Integration: Wave can integrate with payment gateways to enable smooth transaction processing.

 10. Zoho Invoice

Zoho InvoiceThis software features time tracking, expense management, and automated reminders for efficient invoicing.


Time Tracking: Track billable hours and convert them into invoices effortlessly.

Expense Management: Capture expenses and add them to client invoices for reimbursement.

Automated Reminders: Set up payment reminders for clients to ensure timely payments.

Subscription Billing: Manage recurring billing for subscription-based services.

Integration Capabilities:

API Integration: Zoho Invoice offers APIs for integrating with legacy systems and other Zoho Suite products, ensuring seamless data exchange and real-time synchronization.

Customer Support System Integration: Zoho Invoice can integrate with customer support systems, facilitating smoother issue resolution and billing communication.

11. Square Invoices

Square LogoSquare Invoices offers online invoicing, card payments, and sales reporting for streamlined billing and payment processing.


Online Invoicing: Square Invoices facilitates creating and delivering professional online invoices.

Card Payments: Clients can pay invoices online securely using credit cards.

Sales Reporting: Square offers sales reporting and analytics for better financial insights.

Customization: Customize invoice templates to match your brand’s identity.

Integration Capabilities:

API Integration: Square Invoices offers API integration capabilities, enabling seamless communication and data exchange with legacy systems and other applications.

E-commerce Platform Integration: Square Invoices can integrate with e-commerce platforms, automating invoicing for online sales.


Connect the past and present by integrating modern billing software with your legacy system. These 11 billing solutions provide simpler procedures, increased efficiency, and improved client interactions while overcoming issues like outdated technology and restricted integration. Adopt a seamless integration strategy to maximize your billing operations’ potential for development and success.


How do I know if my legacy system is compatible with modern billing software?

You need to check your system’s architecture and integration capabilities. Modern billing solutions like Invoicera provide detailed documentation and compatibility guidelines. Additionally, you can contact the software provider’s support team to find out whether your legacy system can integrate with the billing software.

What is legacy system integration, and why is it essential for billing software? 

Legacy system integration connects modern billing software with older systems, such as outdated accounting software. Integration ensures seamless data transfer, eliminates manual data entry, and streamlines financial processes, leading to increased efficiency and accuracy.

Is data security compromised when integrating billing software with legacy systems?

Data security is a top priority for billing software providers. Reputable billing platforms implement strong security measures to protect sensitive financial data during integration. You must consider all the features and functionalities and decide whether it is reliable and secure.