About US

About Custom QuickBooks

When Intuit decided to open possibilities for software developers to synchronize other applications with its #1 selling line of QuickBooks products, Mainstreet Systems was invited to come to Mountain View in California to explore combining custom software applications with QuickBooks.

Our approach to custom programming is centered on listening to our customers, learning from them and working together to develop new solutions.

Our Skills

C#, Java, ASP.Net, And More

C#, Java, ASP.Net, And More

Programming Languages

Our team has extensive experience working with a wide range of programming languages.
Software Integration

Software Integration

We Know Software

Our team has worked with dozens of different software systems. We can work with you to determine whether your existing software can be modified to meet your needs or if a new system is needed.

Customer Service

Customer Service

Working With People

We have been told many times that we have some of the best customer service and support in the industry.


We know QuickBooks

In the years since Intuit recruited us to synchronize our proprietary software with QuickBooks, we have had considerable success in developing not only this but also custom synchronized solutions for other organizations that are intuitive, capable and reliable.

Our Values

Whats makes us, us.

We strive for transparency – to represent who we are openly and honestly. That means being genuine in our work and relationships, and taking responsibility for our successes and failures.
We’re dedicated to overcoming hurdles and delivering great results. We love what we do and believe that hard work and passion is what drives us forward.
We are respectful of our clients and coworkers. It is our goal to always foster a warm, positive work environment – we don’t participate in negativity or gossip.
We have a long history of amazing customer service. We have made it our mission to consistently deliver on our promises and provide support for our clients’ team and ours.

What We Do Best

New Capabilities


Custom Reporting


Client Interaction


Converting Information




Custom Programming


Web Bases Services


Financial Tracking and More


Let’s Get Started

Ready To Make a Real Change? Let's Build this Thing Together!