Custom Reeleezee integration development
Appfront builds custom Reeleezee integrations that seamlessly connect your online accounting with webshops, payment services, banks, CRM systems and your own applications. Using Reeleezee's official REST API, we build stable integrations that eliminate manual work and keep your bookkeeping consistent.
What is a Reeleezee integration?
Reeleezee is online accounting, invoicing and administration software for sole traders, small and medium-sized businesses and their accountants. Since 2017, Reeleezee has been part of Exact, and the software is also known as Exact Reeleezee. The package offers a REST API through which external systems can read and write sales invoices, general ledger accounts, VAT data, relations and bank data.
A Reeleezee integration automatically connects your online accounting with your webshop, payment service, CRM package or your own application. Data flows from one system to the other without manual work: orders become sales invoices, payments are matched, VAT is booked correctly, and customer and debtor information stays up to date in both directions.
Appfront builds these integrations to measure using the Reeleezee REST API. We tailor the scope, synchronisation frequency and error handling to your actual business processes, rather than relying on a standard connector that only solves part of the problem.
Real-time synchronisation
Changes in Reeleezee or in the connected system are passed on immediately or at an agreed frequency. No overnight imports, just accounting data that stays live.
Bookkeeping that fills itself
Sales invoices, general ledger entries and customer data are processed automatically in Reeleezee. Less error-prone manual work, more time for the figures that really matter.
Via the official REST API
Implementation in line with the Reeleezee REST API using OAuth 2.0, clear error handling and comprehensive logging. No reverse engineering or scraping of the portal.
Our development process for Reeleezee integrations
We follow a proven methodology that removes uncertainty early and delivers a stable integration. From an initial analysis of your accounting entities through to go-live and ongoing management, every step is aimed at an integration your team can understand and trust.
We map out which Reeleezee entities are relevant — invoices, general ledger, VAT, customers — which direction data should flow in and which booking rules apply.
We design the integration architecture, set up OAuth 2.0 authentication and define an error handling strategy.
Implementation with automated tests, structured logging and monitoring. You see working builds along the way.
Controlled go-live with data validation and a safety net, followed by ongoing management and further development.
What a Reeleezee integration delivers in practice
Every integration is developed specifically for your business processes. Below are the features we most often build for organisations that want to connect Reeleezee with the rest of their software landscape.
Reeleezee REST API
We build the integration on Reeleezee's official REST API (base path /api/v1) with OAuth 2.0 authentication. A robust foundation that gives access to virtually all financial and accounting data in your administration.
Sales invoice synchronisation
Sales invoices are automatically created or retrieved in Reeleezee, including invoice lines and VAT codes. Orders from your webshop or CRM are converted into clean bookings without retyping.
General ledger & journal entries
Bookings, ledger accounts and journal entries are exchanged via the API. Your operational data thus aligns seamlessly with the chart of accounts, and the general ledger in Reeleezee stays consistent.
VAT & tax return data
VAT codes and VAT details are correctly applied to every booking, including reduced rates and cross-border supplies. Your VAT overview in Reeleezee remains accurate, without manual corrections afterwards.
Synchronising customers & debtors
Customer and relationship details stay aligned between Reeleezee and your CRM or webshop. New debtors are created automatically, address and payment details stay up to date, and duplicate entry disappears.
Webshop, PSP & bank integration
Orders and payments from webshops (WooCommerce, Shopify, Magento) and payment services (Mollie, Stripe) flow into Reeleezee as invoices and bookings. Bank data can also be made available through the administration for automatic processing.
Typical use cases in practice
Depending on your type of organisation, an integration with Reeleezee can look very different. We see a number of recurring patterns, and for each of them we have developed a working model.
Small and medium-sized business
An SME that keeps its books in Reeleezee doesn't want to maintain its administration by hand. We connect Reeleezee to the systems where invoices and payments originate, so sales invoices, customer records and general ledger entries are processed automatically. See also our custom software.
Webshop & e-commerce
A webshop processing orders every day cannot run on manual bookings. We connect the shop and the payment service to Reeleezee, so orders, customers and payments are automatically converted into invoices and bookings, including VAT logic. See also our e-commerce development.
Accountancy & bookkeeping firms
Many administrations handled by accountancy and bookkeeping firms are kept in Reeleezee. We connect Reeleezee to a client portal, reporting tool or workflow system, so invoices, general ledger and VAT data are exchanged efficiently, with permissions that determine who may view which administration.
Freelancers & service providers
Freelancers and small service providers who keep their books in Reeleezee want to avoid entering invoices and payments twice. We integrate Reeleezee with your booking, planning or payment tool, so sales invoices are created automatically and your accounts stay up to date without retyping.
Technology we use
We build Reeleezee integrations with modern, well-maintained stacks. The exact choice depends on your situation and preferences, so your own team can manage or further develop the integration. We are happy to work alongside other suppliers and deliver clear documentation.
Why choose Appfront for your Reeleezee integration?
Appfront has extensive experience building API integrations for a wide range of organisations in the Netherlands. We always start with a thorough analysis of your existing systems and processes. An integration should not only work technically, but also add practical value to the way you work.
For every integration, we write clear documentation and make sure your own team, or any future supplier, can understand and manage it. No black box, just transparent code and clear agreements on monitoring, alerting and maintenance.
You work with a dedicated point of contact who understands both the technical and the functional side. This keeps communication short, prevents misunderstandings and speeds up decisions when choices need to be made during development.
You may also be interested in our broader services around API integrations, middleware, custom software and web app development. Do you use a different accounting package? We also build integrations with Exact Online, Moneybird and Twinfield. You can find a full overview under our integrations.
- Specialists in Dutch accounting and bookkeeping integrations
- Experience with the Reeleezee REST API and OAuth 2.0
- Structured error handling and retry mechanisms
- Comprehensive logging and monitoring from day one
- Clear documentation your team can read and manage
- A fixed point of contact, no account managers passed around
- Ongoing maintenance and proactive further development
- A way of working aligned with your existing IT landscape
Security and privacy in Reeleezee integrations
Financial data and debtor information largely fall under the GDPR and contain commercially sensitive information. Appfront treats every integration with that in mind: we avoid storing unnecessary data, encrypt sensitive information both in transit and at rest, and document the data flows so that your record of processing activities stays up to date.
Authentication runs via OAuth 2.0 with restricted permissions. As Reeleezee handles financial data and debtor information, authorisations determine exactly which administration and which data an integration may access. We agree in advance which data really needs to be exchanged and minimise the scope of the integration in line with the data minimisation principle, in compliance with GDPR.
More on our security approach: information security policy and CVD policy.
- GDPR-compliant data processing and data minimisation
- Encryption in transit (TLS 1.2+) and at rest
- Role-based access and least-privilege principles
- Audit logs with traceable data flows
- Automatic retries and dead-letter queues
- Monitoring and alerting for anomalies
- Secrets management in line with best practice
- Documentation for your record of processing activities
Frequently asked questions about Reeleezee integrations
Answers to the questions we get asked most often about custom Reeleezee integrations.
A Reeleezee integration is a technical link that lets Reeleezee, the online accounting and invoicing software that has been part of Exact since 2017, exchange data with another software system. This runs through Reeleezee's official REST API. Sales invoices, general ledger accounts, VAT details and relations can then be synchronised automatically with, for example, a webshop, a payment service provider (PSP) or a proprietary application.
A custom integration makes sense when no ready-made connector exists for your combination of systems, or when a standard integration doesn't fit your work processes well enough. Organisations with specific data fields, unusual invoice structures or complex synchronisation logic also often opt for a custom-built solution based on the Reeleezee REST API.
Reeleezee's REST API exposes financial and accounting data such as sales invoices, general ledger accounts, VAT details, relations and debtors, bank details and products. Together with you, we determine which entities are relevant and in which direction the data should flow, so the integration fits your administration exactly.
We work with the official Reeleezee REST API and build the integration layer using modern back-end technologies such as Node.js, Python, Laravel or .NET. Authentication runs via OAuth 2.0. For scheduling, monitoring and error handling, we use tools such as webhooks, job queues and logging dashboards, depending on your requirements.
Yes. Many administrations kept by accountancy and bookkeeping firms are run in Reeleezee. An integration can connect Reeleezee to a client portal, reporting tool or workflow system, so invoices, ledger data and VAT information are exchanged efficiently. Authorisations determine exactly who may view which administration and which data.
Yes. We connect Reeleezee to webshop platforms such as WooCommerce, Shopify or Magento, and to payment service providers (PSPs) such as Mollie or Stripe. Orders and payments are then automatically converted into sales invoices and bookings in Reeleezee, including VAT logic, so your accounts stay up to date without manual work.
Yes. All integrations are developed in line with Dutch privacy legislation and security best practices. We encrypt data in transit and at rest, use OAuth 2.0 with restricted permissions, and minimise the scope of the data exchanged in line with the principle of data minimisation. Financial data and authorisations are carefully protected, and data flows are documented so that your record of processing activities stays complete.
Yes. Appfront regularly takes over existing integrations, including those originally built by another party. We start with a code and architecture review, document the integration and draw up a maintenance plan. From that point on, we can handle adjustments, extensions and monitoring.
Ready to build your Reeleezee integration?
Tell us which systems you want to connect and what you want to automate. We are happy to think along with you on the architecture and deliver a working integration that suits your situation. A no-obligation first conversation will give you a clear picture of the possibilities within half an hour.