About Ultaxa

Accounting done the right way — close to the client.

Nearly 20 years of experience, working directly for you.

Kim Resso, founder and lead accountant at Ultaxa LLC, Northern California

Kim Resso

Founder & Lead Accountant, Ultaxa LLC

I started Ultaxa because I believe accounting should be more than just numbers. It's personal and involves people that look to you for solutions and clarity for their businesses and personal matters.

I spent nearly 20 years in accounting before going out on my own. That experience means I've seen a lot of situations — and I know how to handle the complicated ones.

Most of my clients come to me because something wasn't working. Their books have fallen behind, they're using software that doesn't fit their business or it's becoming too expensive, or they only hear from their accountant during tax season. I help solve those problems, but more importantly, I become a long-term partner. My clients don't have to reintroduce themselves or explain their business every year—I already know their story, which allows me to provide proactive advice and personalized service year after year.

Kim Resso — Enrolled Agent
Experience

A background built over nearly two decades

2005 – 2014

Controller

Managed accounting engagements across a range of industries including retail, construction, and professional services. Built deep expertise in financial reporting, tax compliance, and client advisory work.

2014 – 2024

Senior Accountant

Oversaw full-cycle accounting for a mid-sized manufacturing operation. Managed a small accounting team, implemented accounting software improvements, and served as the primary financial liaison to ownership.

2024 – Present

Ultaxa, LLC

Founded Ultaxa to serve small businesses directly, with the depth of a firm and the accessibility of an in-house partner. Providing bookkeeping, accounting, payroll, tax services, and software consulting to clients across Northern California.

Our Team

Small team. Deep expertise.

Two people focused entirely on getting your books right.

Kim Resso, Founder and Lead Accountant at Ultaxa LLC

Kim Resso

Founder & Lead Accountant

Nearly 20 years of experience. Handles accounting, tax, payroll, and software consulting.

Shelby Resso, Accounting Associate at Ultaxa LLC

Shelby Resso

Accounting Associate

Handles day-to-day bookkeeping, ensuring accurate and timely records every month.

Ready to work with someone who actually knows your business?

Start with a free 30-minute conversation — no commitment required.

Let's Talk