Our partnerships

Wolters Kluwer

Wolters Kluwer: the world's number one in software & services for tax and accounting. ADDISON has been part of Wolters Kluwer Software und Service GmbH since 2008.


Microsoft® is the world's leading manufacturer of operating system and application software. Our close Microsoft® partnership enables us to offer comprehensive support and up-to-date expertise.


CHEFS CULINAR is one of the leading wholesale distributors and supplies customers in the food industry, hotel industry and community feeding.

CISCO Systems

When it comes to security, in addition to Microsoft solutions we rely chiefly on products developed by Cisco Systems, the leading provider of networking solutions for internet connectivity.


Citrix Systems, Inc. is a leading provider of virtualisation technologies that enable businesses to deliver IT as an on-demand service. Citrix gained its reputation first and foremost with software and terminal server applications.

Citrix Xen Server

Management and integration of virtual infrastructures with Citrix XenServer software. Citrix offers unrivalled server consolidation solutions that increase IT security and reduce costs.


HausPerfekt GmbH & Co. KG has firmly established itself on the market as a provider of highly specialised software for professional property management and property administration.


INFOLOG GmbH has been developing practical software systems for many years to reduce the workload of tax departments on a continuous basis. INFOLOG TAX SUITE handles demanding processes such as tax balance sheet preparation, e-balance sheet generation and tax audit workflows in their entirety.


Meffert offers comprehensive e-recruiting software solutions specifically for headhunters, recruitment consultants and agents in the recruiting industry.


The open source platform Nextcloud is the world renowned software solution for encrypted data storage, file synchronisation and online collaboration.


Plesk is a web server tool developed by Parallels Inc. for creating, securing and running websites and applications in the cloud.


The regify group is an international provider of trusted e-communications. regify's patented and data protection-tested technology allows for verifiable and legally compliant e-communication processes.

Ripe NCC Member

Ripe is a Regional Internet Registry (RIR) responsible for allocating IP address ranges and AS numbers in Europe, the Middle East and Central Asia.


ROSESOFT develops software for tax consultants, income tax assistance unions and tax departments. Our focus in on declaring and calculating personal and business taxes in compliance with the law as well as electronic communication with the fiscal authority.


Protects your network infrastructure against internet threats such as hacking, spyware, viruses, phishing, spam and other malware from the web.