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How Accounts Payable Software accelerate ERP Integrations with Unified APIs

Seamless ERP integrations help AP software vendors eliminate manual reconciliation and accelerate financial close. Maesn's Unified API covers the full AP workflow out of the box, from supplier management and invoice processing to payment scheduling and reconciliation.

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Dr. Themo Voswinckel

March 23, 2026

How Accounts Payable Software accelerate ERP Integrations with Unified APIs

Key Takeaways

  • Building and maintaining custom ERP connectors is resource-intensive, costly, and diverts development time away from core product improvements.
  • A unified API replaces individual ERP connectors with a single integration point, reducing complexity and enabling consistent data handling across all systems.
  • Maesn covers the full AP integration workflow: initial mapping, initial sync, and ongoing bidirectional synchronization between AP software and ERP systems.
  • Maesn is officially partnered with all supported ERP and accounting vendors, opening up co-marketing, marketplace listings, and joint campaigns beyond just API access.
  • For teams that do not want to code, Maesn offers Managed Integrations with no-code ready-made flows and a white-glove setup experience.

The Complexity of Traditional ERP Integrations

Integrating AP software with multiple ERP systems traditionally requires developing custom connectors for each platform. This approach presents several challenges:

  • Resource Intensive: Developing and maintaining individual integrations demands significant time and technical expertise, diverting resources from core product development.
  • Scalability Issues: As the number of ERP systems grows, the complexity and cost of maintaining numerous integrations escalate, making it difficult to scale efficiently.
  • Inconsistent Data Handling: Variations in data formats and structures across different ERPs can lead to inconsistencies, increasing the risk of errors and complicating data reconciliation.

What often starts as a straightforward project quickly turns into a resource-intensive effort. Beyond the initial development, maintaining these integrations demands continuous updates, troubleshooting, and adapting to ERP system changes. The real cost isn’t just the upfront investment—it’s the long-term commitment to ongoing maintenance, which can quietly consume tens of thousands of euros annually.

Additionally, there’s an often-overlooked opportunity cost: every hour spent on integration work is time taken away from refining your product, launching new features, or addressing customer needs. In fast-moving Software environments, this delay can hinder innovation and slow down growth.

Unified APIs: A Streamlined Approach to ERP Integration

Maesn’s Unified API provide a standardized interface that allows AP software vendors to connect with multiple ERP systems through a single integration point. This approach offers several key advantages:

  • Simplified Integration Process: By interacting with our Unified API, vendors can avoid the intricacies of individual ERP, reducing development time and complexity.

·       Shortcut Partnering: Immediate access to sandboxes and required infrastructure.

  • Enhanced Scalability: A single integration enables connectivity to various ERP systems, allowing vendors to expand their offerings without proportional increases in integration efforts.
  • Consistent Data Management: Unified APIs standardize data formats, ensuring consistent data handling across different platforms and improving data accuracy.

Practical Implementation: Synchronizing AP Software with ERP Systems

Implementing a Unified API for ERP integrations involves several key workflows, that needs be enabled for a comprehensive integration between the AP software and ERP Software:

Initial Mapping:
  • Objective: Establish a one-time mapping between AP software objects and corresponding ERP entities.
  • Process: Enable mapping of various objects in the AP software to the ERP system, aligning data fields and structures.
  • Maesn Unified API Endpoints:

GET companies, GET accounts

Initial Synchronization:
  • Objective: Perform a comprehensive data sync to ensure both systems are aligned.
  • Process: Synchronize e.g. payment terms, general ledger (GL) accounts, custom dimensions, taxes, units and payees (suppliers) from the ERP to the AP software.
  • Maesn Unified API Endpoints:

GET paymentterms, GET accounts, GET dimensions, GET suppliers

Ongoing Synchronization from ERP to AP Software:
  • Objective: Maintain data consistency by continuously updating the AP software with changes from the ERP system.
  • Process: Reflect additions, updates, or deletions of objects as well as purchase orders and good received receipts in the ERP within the AP software.
  • Maesn Unified API Endpoints:

GET paymentTerms, GET accounts, GET dimensions

Ongoing Synchronization from AP Software to ERP:
  • Objective: Ensure the ERP system remains updated with the latest data from the AP software.
  • Process: Continuously synchronize payees/suppliers, bills, vendor credits, and payments from the AP software to the ERP.
  • Unified API Endpoints:

POST suppliers, POST bills, POST vendorcredits, POST payments

Maesn’s Unified API – Your Key to Scalable ERP Integrations

A Smarter Approach to ERP & Accounting Integrations

Maesn’s Unified API delivers a seamless and efficient solution for software vendors that need to integrate with multiple ERP and accounting platforms. Our standardized API eliminates the complexity of building individual integrations, enabling effortless data synchronization between business-critical systems. But Maesn is more than just an API provider. We are a strategic technology partner that empowers your growth.

Cost-Effective Scalability for Software Vendors

With a single integration, software vendors can connect to leading European ERP and accounting platforms, including DATEV, Microsoft Dynamics, Xero, Sage, bexio, holded, Exact and many more. Instead of allocating extensive resources to build and maintain custom integrations, vendors can leverage Maesn’s API to streamline and accelerate their connectivity.

Deep European Market Expertise

As a Germany-based company with a strong European presence, Maesn understands the intricacies of regional ERP and accounting systems. Many European countries rely on specialized financial software, making scalability a challenge for software vendors. With Maesn’s deep market expertise and technical know-how, you get the best integration experience tailored to the tools your customers actually use.

Expand Your Market Potential and Win More Deals

Potential customers expect software solutions that integrate seamlessly with their existing financial tools. Each new ERP and accounting integration extends your Total Addressable Market (TAM), unlocking new customer segments and accelerating your sales pipeline. By offering a broad set of integrations, you make your product more attractive and improve conversion rates.

Speed Up Product Development & Reduce Churn

By outsourcing ERP integrations to Maesn’s scalable solution, your developers can focus on core product improvements rather than managing complex integrations. Faster feature rollouts, better user experience, and continuous improvements help you meet customer expectations while minimizing churn.

Developer-First Integration Experience

We recognize that software development is complex, which is why we provide intuitive, developer-friendly tools:

  • API Documentation: Clear and standardized guides to simplify development
  • Postman Collection: Monitor API performance, track usage, and gain insights into activation metrics
  • Dev Sandboxes: We provide you sandboxes if the systems don’t
  • Enterprise-Grade Security: Hosted in Germany with stringent security measures, encrypted data flows, and secure authentication processes
Empower Your Marketing and Partnership Strategy

Unlike other unified API providers, Maesn is strongly partnered with ALL supported ERP and accounting vendors instead of just leveraging their public APIs. Our strong partnerships open up co-marketing opportunities, including:

  • Marketplace listings within ERP and accounting platforms
  • Joint marketing campaigns to drive visibility and adoption
  • In-app promotions to maximize integration awareness

No resources? Talk to us regarding our Managed Integration Offer

With Maesn’s Unified API, you gain instant access to a broad range of ERP and accounting integrations. If a specific system isn’t yet available, our roadmap allows for rapid expansion.

But for those who don’t feel like coding at all, we offer Maesn Managed Integration. With Managed Integrations, we integrate your API to our Unified APIs to offer you no-code ready-made flows. You decide how your users activate integrations, if you want to embedded it or via a dedicated marketplace - for a true white glove experience.

Trusted by Leading Software Teams

Fast-growing software vendors rely on Maesn to simplify their ERP and accounting integrations. Our Unified API enables them to scale faster, reduce development overhead, and enhance customer satisfaction.

Take a strategic step toward seamless ERP integrations and unlock new business opportunities with Maesn. Let’s discuss how our solution can help you scale efficiently and drive long-term success.

Curious about how Maesn’s Unified API can accelerate your ERP integrations? Get in touch today!

About the author

Themo is CEO and Co-Founder of Maesn. With years in strategy consulting — spanning requirements engineering for complex software landscapes, ERP and accounting software selections, and end-to-end integration projects — he holds a Dr.-Ing. with a focus on ERP-to-SaaS transformation. He co-founded Maesn to make system integration effortless.

Dr. Themo Voswinckel

Co-Founder

Frequently asked
questions

You have more questions? We are looking forward hearing from you - book a meeting now!

Why is traditional ERP integration so expensive to maintain?

Custom connectors require continuous updates, troubleshooting, and adaptation to ERP changes. Beyond the initial development cost, ongoing maintenance can quietly consume tens of thousands of euros annually, while diverting engineering time away from product development.

What is a unified API and how does it help AP software vendors?

A unified API provides a single integration point that connects to multiple ERP systems simultaneously. Instead of building and maintaining separate connectors per system, vendors integrate once with Maesn and gain access to all supported platforms with consistent data formats and standardized endpoints.

What data needs to be synchronized between AP software and ERP systems?

A complete integration covers initial mapping of objects and accounts, an initial sync of payment terms, GL accounts, taxes, dimensions, and suppliers, followed by ongoing bidirectional sync. This includes purchase orders and receipts from the ERP, and bills, vendor credits, and payments from the AP software.

Which ERP and accounting systems does Maesn support?

Maesn supports leading European platforms including DATEV, Microsoft Dynamics, Xero, Sage, bexio, Holded, Exact, and many more, with ongoing expansion based on customer demand.

What if we do not have the resources to build the integration ourselves?

Maesn offers Managed Integrations, a no-code option where Maesn integrates your API into its unified layer and delivers ready-made flows. You choose how users activate integrations, either embedded in your product or via a dedicated marketplace.

What makes Maesn different from other unified API providers?

Maesn holds official partnerships with all supported ERP and accounting vendors rather than simply using their public APIs. This enables co-marketing opportunities, marketplace listings, joint campaigns, and in-app promotions that other providers cannot offer.

Kickstart your Integration Journey now