InvoiceNinja is a powerful open-source software for invoicing, online payments, expense tracking, and project management. The platform is specifically designed for freelancers and small businesses, offering all the tools needed for professional financial and business management.
Leading companies worldwide trust WZ-IT
The following are trademarks of their respective owners: Invoice Ninja (InvoiceNinja, LLC). WZ-IT is an independent service provider and has no business, partnership, or contractual relationship with these companies. We offer independent migration, installation, hosting, and operations services.
InvoiceNinja is a powerful open-source software for invoicing, online payments, expense tracking, and project management. The platform is specifically designed for freelancers and small businesses, offering all the tools needed for professional financial and business management.
As an experienced InvoiceNinja partner, we support you in installing, configuring, and customizing this versatile business solution to your individual requirements. Leverage the benefits of automated invoicing and professional client communication for your business.
We install, host and operate InvoiceNinja for your company - either on our secure, GDPR-compliant infrastructure in Germany or other locations, as well as on-premise in your own environment.
With 24/7 monitoring, backups and professional maintenance, we ensure maximum availability and reliable operation of your Invoice Ninja instance. Note: we install Invoice Ninja as a dedicated instance per customer. White-label branding (removing the Invoice Ninja logo) requires a white-label license from Invoice Ninja LLC (~USD 40/year per instance) - we are happy to procure it on your behalf.
We install Invoice Ninja as a dedicated instance per customer. White-label setups (removing Invoice Ninja branding) require a separate white-label license from Invoice Ninja LLC (~USD 40/year per instance).
We take over full operations - installation, configuration, updates, monitoring, backups and support - on your dedicated instance; we are happy to procure the WL license on your behalf if needed.
Create and send unlimited invoices with real-time PDF preview, customizable templates, recurring invoices, and automatic reminder functionality.
Integration with numerous payment gateways like Stripe, PayPal, Braintree, Square, Mollie, and more for fast online payments and automatic status updates.
Create professional quotes that can be automatically converted to invoices upon approval, enabling a seamless sales process.
Manage projects with Kanban boards, track tasks and working hours, and convert them into invoice items with a single click.
Track expenses, import receipts, categorize costs, and bill them to clients if needed, with optional bank account integration.
Provide your clients access to a personalized portal where they can view invoices, make payments, and download documents.
Gain detailed insights into your finances with revenue reports, client statements, aging cohorts, and customizable reporting options.
Customize invoice designs, email templates, numbering sequences, and user permissions to match your specific business requirements.
Connect InvoiceNinja with Zapier, Make, Pabbly, and other services for automated workflows and seamless integration into your existing tool landscape.
See how simple and efficient InvoiceNinja works in practice. From installation to productive use.
Professional installation on your infrastructure - on-premise, cloud or hybrid
In your data center
AWS, Azure, Hetzner & more
High-availability setup with comprehensive security and compliance features
Secure access and access control for your installation
WireGuard, NetBird or Tailscale
Keycloak, Authentik, Azure AD
TOTP, WebAuthn, YubiKey
Fail2Ban, Rate Limiting, IP Whitelisting
We set up secure VPN access to your installation - ideal for remote work and external employees.
Full-service installation with no hidden costs
InvoiceNinja is powerful, but German requirements (ZUGFeRD, special layouts) are often tricky. We use the Laravel foundation for customizations beyond the UI.
We integrate invoicing completely invisibly into your app. Your system fires an API call, InvoiceNinja creates, sends, and reminds the invoice fully automatically.
Invoice paid? We use webhooks to unlock the service in your system, trigger shipping, or send a 'Thank You' SMS to the customer.
The standard editor has limits. We code PDF templates directly in HTML/CSS/Blade. Pixel-perfect implementation of your stationery, conditional texts (EU Reverse Charge), and dynamic QR codes.
How we implement InvoiceNinja development in practice.
The tax advisor needs data in a specific CSV/XML format that InvoiceNinja does not natively export.
An external script that pulls all new invoices monthly via API, maps account assignment information, and generates a DATEV-compliant export file.
Billing is based on usage, not fixed prices. Standard recurring invoices cannot handle this.
A cronjob service that aggregates usage data from your app at month-end and generates an invoice with dynamic line items in InvoiceNinja via API.
Customers should not be redirected to an external URL (invoice.domain.com) for invoices and payments.
Integration of the client portal via IFrame or API into your own login area. Seamless UX without media breaks.
Open source enterprise-ready for productive workloads - we run your applications with highest security standards and enterprise support
Open Source Software für geschäftskritische Prozesse erfordert professionelle Wartung, kontinuierliche Updates und enterprise-grade Support. Wir übernehmen Hosting und Betrieb von InvoiceNinja auf unserer DSGVO-konformen Infrastruktur in Deutschland (oder optional in Ihrer Cloud) - inklusive Backups, SLAs, Telefon-Support und persönlichem Ansprechpartner. Damit Sie sich auf Ihr Kerngeschäft konzentrieren können.
Wir bieten auch maßgeschneiderte Hosting- und Entwicklungs-Lösungen für Ihre speziellen Anforderungen rund um InvoiceNinja. Kontaktieren Sie uns für ein individuelles Angebot.
Whether you run InvoiceNinja in-house or need to host confidentiality-professional data §203-ready - we build, operate and maintain InvoiceNinja on an encrypted on-site server. Data never leaves the building in cleartext.
See InvoiceNinja on-premise
Good choice - we'll help you get started or with operations.
As a Managed Service customer at WZ-IT, you have access to our exclusive portal: Monitor your infrastructure in real-time, schedule maintenance, request quotes, and get direct support - all in one central location.
These solutions are often used together with Invoice Ninja
These solutions offer similar functionalities and can be evaluated together
No risk: worst case, you leave with a clearer understanding of your project than before.
“WZ-IT's advice on our Azure migration was technically sound and completely non-binding right from the intro call - we took away a great deal.”
“Professional, honest and technically thoroughly sound: WZ-IT set up our Proxmox and backup infrastructure securely and future-proof. The consulting from Timo and Robin was objective and needs-driven, the implementation smooth and the final documentation exemplary. You can tell immediately that business-critical infrastructure is thought through holistically from the outset here and implemented with clear ownership.”
Pascal Block
Project Manager, Stadtwerke Brühl GmbH
Stadtwerke Brühl - municipal energy and infrastructure utility.
“Communication with WZ-IT was open, friendly and professional from the very beginning. Mr. Wevelsiep and Mr. Zins responded to every one of our questions patiently, promptly and respectfully, and contributed their own suggestions and good ideas on how to modernize our server infrastructure and adapt it even better to our needs. Throughout, WZ-IT consistently kept our need for data sovereignty and GDPR compliance in mind. Even short-notice adjustments and change requests from our side were implemented quickly and patiently and integrated consistently into the overall concept. From planning to the final handover, every step was documented transparently and comprehensively - so if a provider change should ever become necessary, the documentation would let us onboard a successor into our infrastructure very quickly. We are extremely satisfied with WZ-IT and hope to continue working together for a long time.”
Christoph Mußmann
Project Officer, DGHO e.V.
DGHO - German Society for Hematology and Medical Oncology.
“I got to know Timo and Robin as dedicated and professional partners who make a lot of things possible for their clients that initially seem impossible. I felt very well advised. The services offered have thoroughly convinced me. (translated)”
Andrea Pawlowski
Communications Manager, Golem.de
Golem.de - leading German IT news outlet.
“While looking for a partner to integrate a local AI solution, we came across Timo and Robin - and could not have made a better decision. They quickly understood our requirements and solved technical challenges competently and pragmatically. We were particularly impressed by the straightforward collaboration, their high level of expertise and the speed of implementation. We are delighted to have Timo and Robin at our side as reliable business partners and look forward to our next projects together. (translated)”
Henrik Jeche
Head of IT Administration
ml&s - full-service provider for the electronics industry.
“With Timo and Robin, you're not only on the safe side technically - you also get the best human support! Whether it's quick help in everyday life or complex IT solutions: the guys from WZ-IT think along with you, act quickly and speak a language you understand. The collaboration is uncomplicated, reliable and always on an equal footing. That makes IT fun - and above all: it works! Big thank you to the team! (translated)”
Sonja Aßer
Data Manager, ARGE
ARGE Neue Medien - master data & digital standards for plumbing and building technology.
“I recently worked with Timo and the WZ-IT team, and honestly, it turned out to be one of the best tech decisions I have made for my business. Right from the start, Timo took the time to walk me through every step in a simple and calm way. No matter how many questions I had, he never rushed me. The results speak for themselves. With WZ-IT, we reduced our monthly expenses from $1,300 down to $250. This was a huge win for us.”
Aleksandr Shuliko
CTO, EVA Real Estate, UAE
EVA Real Estate - leading real-estate agency in Dubai.
“WZ-IT manages our Proxmox cluster reliably and professionally. The team handles continuous monitoring and regular updates for us and responds very quickly to any issues or inquiries. They also configure new nodes, systems, and applications that we need to add to our cluster. With WZ-IT's proactive support, our cluster and the business-critical applications running on it remain stable, and high availability is consistently ensured. We value the professional collaboration and the noticeable relief it brings to our daily operations.”
Pascal Hakkers
Aphy AG, Switzerland
Aphy AG - AI platform for hotel back-office.
“WZ-IT provided very competent support in implementing our server and virtualization infrastructure. As part of the project, a Proxmox-based virtualization environment was set up along with a virtual machine for our application systems. Additionally, a structured backup concept was implemented. A particular focus was on security: the setup of a VPN tunnel and the clean implementation of encryption and access concepts were professionally executed. The structured consulting as well as the reliable and swift implementation deserve special mention. We are very satisfied with the services provided and are happy to recommend WZ-IT.”
John Hellmerichs
Managing Director, AInergy GmbH
AInergy - consultancy for energy and facility management.
“We have had very good experiences with Mr. Wevelsiep and WZ-IT. The consultation was professional, clearly understandable, and at fair prices. The team not only implemented our requirements but also thought along and proactively. Instead of just processing individual tasks, they provided us with well-founded explanations that strengthened our own understanding. WZ-IT took a lot of pressure off us with their structured approach - that was exactly what we needed and is the reason why we keep coming back. (translated)”
Matthias Zimmermann
Managing Director, Annota GmbH
Annota - healthtech startup with an AI documentation assistant.
“Timo and Robin from WZ-IT set up a RocketChat server for us - and I couldn't be more satisfied! From the initial consultation to the final implementation, everything was absolutely professional, efficient, and to my complete satisfaction. I particularly appreciate the clear communication, transparent pricing, and the comprehensive expertise that both bring to the table. Even after the setup, they take care of the maintenance, which frees up my time enormously and allows me to focus on other important areas of my business - with the good feeling that our IT is in the best hands. I can recommend WZ-IT without reservation and look forward to continuing our collaboration! (translated)”
Sebastian Maier
Managing Director, Yonju GmbH
Yonju - business coaching and AI products.
“Counting on WZ-IT team was crucial, their expertise and solutions gave us the pace to deploy in production our services, even suggesting and performing improvements over our configuration and setup. We expect to keep counting on them for continuous maintenance of our services and implementation of new solutions.”
Gabriel Sanz Señor
Managing Director, Odiseo Solutions
Odiseo Solutions - software engineering for the space industry.
“Professional, honest and technically thoroughly sound: WZ-IT set up our Proxmox and backup infrastructure securely and future-proof. The consulting from Timo and Robin was objective and needs-driven, the implementation smooth and the final documentation exemplary. You can tell immediately that business-critical infrastructure is thought through holistically from the outset here and implemented with clear ownership.”
Pascal Block
Project Manager, Stadtwerke Brühl GmbH
Stadtwerke Brühl - municipal energy and infrastructure utility.
“Communication with WZ-IT was open, friendly and professional from the very beginning. Mr. Wevelsiep and Mr. Zins responded to every one of our questions patiently, promptly and respectfully, and contributed their own suggestions and good ideas on how to modernize our server infrastructure and adapt it even better to our needs. Throughout, WZ-IT consistently kept our need for data sovereignty and GDPR compliance in mind. Even short-notice adjustments and change requests from our side were implemented quickly and patiently and integrated consistently into the overall concept. From planning to the final handover, every step was documented transparently and comprehensively - so if a provider change should ever become necessary, the documentation would let us onboard a successor into our infrastructure very quickly. We are extremely satisfied with WZ-IT and hope to continue working together for a long time.”
Christoph Mußmann
Project Officer, DGHO e.V.
DGHO - German Society for Hematology and Medical Oncology.
“I got to know Timo and Robin as dedicated and professional partners who make a lot of things possible for their clients that initially seem impossible. I felt very well advised. The services offered have thoroughly convinced me. (translated)”
Andrea Pawlowski
Communications Manager, Golem.de
Golem.de - leading German IT news outlet.
“While looking for a partner to integrate a local AI solution, we came across Timo and Robin - and could not have made a better decision. They quickly understood our requirements and solved technical challenges competently and pragmatically. We were particularly impressed by the straightforward collaboration, their high level of expertise and the speed of implementation. We are delighted to have Timo and Robin at our side as reliable business partners and look forward to our next projects together. (translated)”
Henrik Jeche
Head of IT Administration
ml&s - full-service provider for the electronics industry.
“With Timo and Robin, you're not only on the safe side technically - you also get the best human support! Whether it's quick help in everyday life or complex IT solutions: the guys from WZ-IT think along with you, act quickly and speak a language you understand. The collaboration is uncomplicated, reliable and always on an equal footing. That makes IT fun - and above all: it works! Big thank you to the team! (translated)”
Sonja Aßer
Data Manager, ARGE
ARGE Neue Medien - master data & digital standards for plumbing and building technology.
“I recently worked with Timo and the WZ-IT team, and honestly, it turned out to be one of the best tech decisions I have made for my business. Right from the start, Timo took the time to walk me through every step in a simple and calm way. No matter how many questions I had, he never rushed me. The results speak for themselves. With WZ-IT, we reduced our monthly expenses from $1,300 down to $250. This was a huge win for us.”
Aleksandr Shuliko
CTO, EVA Real Estate, UAE
EVA Real Estate - leading real-estate agency in Dubai.
“WZ-IT manages our Proxmox cluster reliably and professionally. The team handles continuous monitoring and regular updates for us and responds very quickly to any issues or inquiries. They also configure new nodes, systems, and applications that we need to add to our cluster. With WZ-IT's proactive support, our cluster and the business-critical applications running on it remain stable, and high availability is consistently ensured. We value the professional collaboration and the noticeable relief it brings to our daily operations.”
Pascal Hakkers
Aphy AG, Switzerland
Aphy AG - AI platform for hotel back-office.
“WZ-IT provided very competent support in implementing our server and virtualization infrastructure. As part of the project, a Proxmox-based virtualization environment was set up along with a virtual machine for our application systems. Additionally, a structured backup concept was implemented. A particular focus was on security: the setup of a VPN tunnel and the clean implementation of encryption and access concepts were professionally executed. The structured consulting as well as the reliable and swift implementation deserve special mention. We are very satisfied with the services provided and are happy to recommend WZ-IT.”
John Hellmerichs
Managing Director, AInergy GmbH
AInergy - consultancy for energy and facility management.
“We have had very good experiences with Mr. Wevelsiep and WZ-IT. The consultation was professional, clearly understandable, and at fair prices. The team not only implemented our requirements but also thought along and proactively. Instead of just processing individual tasks, they provided us with well-founded explanations that strengthened our own understanding. WZ-IT took a lot of pressure off us with their structured approach - that was exactly what we needed and is the reason why we keep coming back. (translated)”
Matthias Zimmermann
Managing Director, Annota GmbH
Annota - healthtech startup with an AI documentation assistant.
“Timo and Robin from WZ-IT set up a RocketChat server for us - and I couldn't be more satisfied! From the initial consultation to the final implementation, everything was absolutely professional, efficient, and to my complete satisfaction. I particularly appreciate the clear communication, transparent pricing, and the comprehensive expertise that both bring to the table. Even after the setup, they take care of the maintenance, which frees up my time enormously and allows me to focus on other important areas of my business - with the good feeling that our IT is in the best hands. I can recommend WZ-IT without reservation and look forward to continuing our collaboration! (translated)”
Sebastian Maier
Managing Director, Yonju GmbH
Yonju - business coaching and AI products.
“Counting on WZ-IT team was crucial, their expertise and solutions gave us the pace to deploy in production our services, even suggesting and performing improvements over our configuration and setup. We expect to keep counting on them for continuous maintenance of our services and implementation of new solutions.”
Gabriel Sanz Señor
Managing Director, Odiseo Solutions
Odiseo Solutions - software engineering for the space industry.
“Professional, honest and technically thoroughly sound: WZ-IT set up our Proxmox and backup infrastructure securely and future-proof. The consulting from Timo and Robin was objective and needs-driven, the implementation smooth and the final documentation exemplary. You can tell immediately that business-critical infrastructure is thought through holistically from the outset here and implemented with clear ownership.”
Pascal Block
Project Manager, Stadtwerke Brühl GmbH
Stadtwerke Brühl - municipal energy and infrastructure utility.
“Communication with WZ-IT was open, friendly and professional from the very beginning. Mr. Wevelsiep and Mr. Zins responded to every one of our questions patiently, promptly and respectfully, and contributed their own suggestions and good ideas on how to modernize our server infrastructure and adapt it even better to our needs. Throughout, WZ-IT consistently kept our need for data sovereignty and GDPR compliance in mind. Even short-notice adjustments and change requests from our side were implemented quickly and patiently and integrated consistently into the overall concept. From planning to the final handover, every step was documented transparently and comprehensively - so if a provider change should ever become necessary, the documentation would let us onboard a successor into our infrastructure very quickly. We are extremely satisfied with WZ-IT and hope to continue working together for a long time.”
Christoph Mußmann
Project Officer, DGHO e.V.
DGHO - German Society for Hematology and Medical Oncology.
“I got to know Timo and Robin as dedicated and professional partners who make a lot of things possible for their clients that initially seem impossible. I felt very well advised. The services offered have thoroughly convinced me. (translated)”
Andrea Pawlowski
Communications Manager, Golem.de
Golem.de - leading German IT news outlet.
“While looking for a partner to integrate a local AI solution, we came across Timo and Robin - and could not have made a better decision. They quickly understood our requirements and solved technical challenges competently and pragmatically. We were particularly impressed by the straightforward collaboration, their high level of expertise and the speed of implementation. We are delighted to have Timo and Robin at our side as reliable business partners and look forward to our next projects together. (translated)”
Henrik Jeche
Head of IT Administration
ml&s - full-service provider for the electronics industry.
“With Timo and Robin, you're not only on the safe side technically - you also get the best human support! Whether it's quick help in everyday life or complex IT solutions: the guys from WZ-IT think along with you, act quickly and speak a language you understand. The collaboration is uncomplicated, reliable and always on an equal footing. That makes IT fun - and above all: it works! Big thank you to the team! (translated)”
Sonja Aßer
Data Manager, ARGE
ARGE Neue Medien - master data & digital standards for plumbing and building technology.
“I recently worked with Timo and the WZ-IT team, and honestly, it turned out to be one of the best tech decisions I have made for my business. Right from the start, Timo took the time to walk me through every step in a simple and calm way. No matter how many questions I had, he never rushed me. The results speak for themselves. With WZ-IT, we reduced our monthly expenses from $1,300 down to $250. This was a huge win for us.”
Aleksandr Shuliko
CTO, EVA Real Estate, UAE
EVA Real Estate - leading real-estate agency in Dubai.
“WZ-IT manages our Proxmox cluster reliably and professionally. The team handles continuous monitoring and regular updates for us and responds very quickly to any issues or inquiries. They also configure new nodes, systems, and applications that we need to add to our cluster. With WZ-IT's proactive support, our cluster and the business-critical applications running on it remain stable, and high availability is consistently ensured. We value the professional collaboration and the noticeable relief it brings to our daily operations.”
Pascal Hakkers
Aphy AG, Switzerland
Aphy AG - AI platform for hotel back-office.
“WZ-IT provided very competent support in implementing our server and virtualization infrastructure. As part of the project, a Proxmox-based virtualization environment was set up along with a virtual machine for our application systems. Additionally, a structured backup concept was implemented. A particular focus was on security: the setup of a VPN tunnel and the clean implementation of encryption and access concepts were professionally executed. The structured consulting as well as the reliable and swift implementation deserve special mention. We are very satisfied with the services provided and are happy to recommend WZ-IT.”
John Hellmerichs
Managing Director, AInergy GmbH
AInergy - consultancy for energy and facility management.
“We have had very good experiences with Mr. Wevelsiep and WZ-IT. The consultation was professional, clearly understandable, and at fair prices. The team not only implemented our requirements but also thought along and proactively. Instead of just processing individual tasks, they provided us with well-founded explanations that strengthened our own understanding. WZ-IT took a lot of pressure off us with their structured approach - that was exactly what we needed and is the reason why we keep coming back. (translated)”
Matthias Zimmermann
Managing Director, Annota GmbH
Annota - healthtech startup with an AI documentation assistant.
“Timo and Robin from WZ-IT set up a RocketChat server for us - and I couldn't be more satisfied! From the initial consultation to the final implementation, everything was absolutely professional, efficient, and to my complete satisfaction. I particularly appreciate the clear communication, transparent pricing, and the comprehensive expertise that both bring to the table. Even after the setup, they take care of the maintenance, which frees up my time enormously and allows me to focus on other important areas of my business - with the good feeling that our IT is in the best hands. I can recommend WZ-IT without reservation and look forward to continuing our collaboration! (translated)”
Sebastian Maier
Managing Director, Yonju GmbH
Yonju - business coaching and AI products.
“Counting on WZ-IT team was crucial, their expertise and solutions gave us the pace to deploy in production our services, even suggesting and performing improvements over our configuration and setup. We expect to keep counting on them for continuous maintenance of our services and implementation of new solutions.”
Gabriel Sanz Señor
Managing Director, Odiseo Solutions
Odiseo Solutions - software engineering for the space industry.
Whether a specific IT challenge or just an idea - we look forward to the exchange. In a brief conversation, we'll evaluate together if and how your project fits with WZ-IT.
Leading companies trust WZ-IT
Timo Wevelsiep & Robin Zins
Managing Directors of WZ-IT
