Arista Business Services LLC

I Focus on Your Books - You focus on your Business.

My name is Mark Thalmann, Owner of Arista Business Services LLC, and I take a great deal of pride in assisting small Business Owners with their financial record keeping, so they have more time to concentrate on what they do best - growing their core business and making money.  

Enjoy the peace of mind and freedom that comes with knowing your books are current, reliable and accurate each month.


Featured Services

QuickBooks Setup / Training


If you are not getting what you need out of QuickBooks, I can help tailor QuickBooks to YOUR business, answer your specific questions and  teach you how to do things the right way.

I'll design a Custom Training Program for you.

QuickBooks Clean up / Catch up


 Are your numbers off and you don't know why? Was your last Bookkeeper inexperienced or did they leave and now you are months behind on data entry? 

 Let me make sure your data is correct and current, then show you how to keep it that way.

Outsourced Bookkeeping Services


 By outsourcing your bookkeeping, you can reduce your overhead costs significantly compared to an in-house hire, free up time you normally spend on the books and get back to what you do best - growing your business.

I'll focus on your books, you focus on your business.

Why Use me?

Mark Thalmann

Expert Attention

  • I do all work myself.  100% US Based, no outsourcing your sensitive financial data.


  • I have been doing the books for Small Businesses for over 25 years, working with hundreds of businesses across all kinds of industries.

Training / Certifications

  • I am a Certified Bookkeeper, held to the highest ethical standards for the profession. 
  • I am ADVANCED Certified in QuickBooks, their highest level and achieved only 2% of ProAdvisors.
  • Committed to staying current with ongoing Continuing Education.
  • Educated on technology that can be beneficial to my Clients.

Piece Of Mind

  • Sit back.  Relax.  Breathe.  Your books are in good hands.
  • Now you can focus on Growing your Business.


TSheets Certified Pro
Chicago Bookkeeping
TIme Tracking
Job Costing
Certified Bookkeeper Chicago