Create MS Office add-in /plugin for Outlook,
Excel, Word in Visual Studio: VB.NET, C#, C++
Add-in Express for Office and .NET is your all-in-one framework for developing commercial class Microsoft Office extensions such as Office COM Add-in, Outlook plugin, Excel XLL, UDF, RTD Server and smart tag.
It works with all editions of Visual Studio, including Express, and all versions of Microsoft Office from 2000 to Office 2021/365.
Create world-class Office extensions
Add-in Express provides you with a range of visual designers, components, Visual Studio item and project templates and deployment tools that make creating quality Microsoft Office extensions easy and fun.
You no longer need to worry about implementing extensibility COM interfaces or hand coding your Office add-in UI using XML. Add-in Express makes deploying your applications a one-click operation and removes the headache of manually creating deployment scenarios and working with the Windows registry. Hard to believe? Just read real stories from real developers.
One project for all Office versions and applications
Add-in Express has an optimized version-neutral core that is written in C# and is based on the .NET framework, COM interoperability and low-level Windows API. This makes it easy for you to create one Visual Studio project that supports all versions (2000 through 2021) and editions (Student, Home, Professional etc.) of Microsoft Office and target multiple applications in the Microsoft Office suite (Outlook, Word, Excel, PowerPoint and other apps.)
100% compatibility from version to version
You are not limited in your choice of Visual Studio versions (2012- 2022) or editions (Professional, Premium, Ultimate etc.) when developing with Add-in Express.
We have always complied with the simple rule that a project built on a prior version of Add-in Express must be 100% compatible with the next version of Add-in Express. This means that after installing the latest version of Add-in Express, you simply open your project and rebuild it� That's it!
Over 10,000 developers trust Add-in Express
Over 10 000 developers around the world already trust Add-in Express to help them create world-class Microsoft Office extensions. When you choose Add-in Express you can rely on our more than 10 years of experience in Microsoft Office development.
After all, Add-in Express was developed for our own add-ins and we still use it to this day for all our end-user solutions. We've invested a lot of time and resources in the development of Add-in Express and all our projects that are based on Add-in Express' tools, take far less time and effort than any of our competitors' products.
Over 40,000,000 PCs have Add-in Express run-time installed
Add-in Express based solutions have been tested, trusted and chosen by over 40 million users all over the world. From startups to international holdings, from student campuses to corporate networks... What about your own machine? :)
Support - the most important feature
There is nothing worse than buying a product and not getting timeous and accurate support. Rest assured that you will never find yourself in this situation with Add-in Express, see what our customers say:
Best of all is not that it is working flawlessly. The support level is outstanding! The answer is always friendly, straightforward and leads to a solution. Thomas Wetzel, Wisco
With Add-in Express I have absolutely no concerns that my query will be dealt with promptly, accurately and with great courtesy.
To have a better understanding of what kind of support you will actually get, read more customer stories.
Add-in Express for .net features and benefits