Entity Restructuring & Strategy
Audit-level rigor applied to save owners money on tax burden, not just filing.
Learn moreNumbers, without surprises.
Numbers, without surprises.
Numbers in plain English. Filed on time. Backed by a real person.
26+ years · Denver
- Years in business
- 26+
- Clients served
- 240+
- Client retention
- 98%
- Average client rating
- 4.8
Years in business
Clients served
Client retention
Average client rating
What we do
Our services
A full range of tax accountant services, handled under one accountable team.
Small-Business Bookkeeping
Clean records monthly so tax time isn't a scramble.
Learn moreFederal & State Tax Filing
On-time, every time, with zero surprises on the bill.
Learn moreIRS Representation & Defense
When the IRS calls, Diane's in the room—not a third-party firm.
Learn moreOwner-Operator Tax Planning
Strategies built for how you actually run the business, not a template.
Learn moreYear-Round Advisory
Same-day responses and proactive planning between filings.
Learn moreWhy us
Why clients choose Summit Tax Advisors
Unusually patient with numbers
Explains tax strategy and bookkeeping in plain English; reviewers note Diane translates complexity without talking down.
Big Four rigor, small-business focus
Twenty-five years of audit practice applied to owner-operated businesses, not Fortune 500 boilerplate.
Same-day responses, real person answers
Diane or her team picks up; no waiting for callbacks or generic email templates.
Saves money on year one
Restructuring and strategy advice routinely delivers five-figure tax savings before the first return is filed.
Denver-rooted, owner-operated itself
A six-person practice where you work with the same people every year, not rotating associates.
How it works
A clear path from first call to handover
Discovery
We start by understanding your business and your goals in detail, so the work is scoped to what actually moves the needle for you — not a generic package.
Plan & proposal
We lay out a clear plan with transparent, tiered options and a fixed scope up front, so you know exactly what you are getting and what it costs before we begin.
Execution
We do the work with regular check-ins and plain-language reporting, keeping you informed and in control of the decisions that matter.
Review & ongoing partnership
We measure results against the goals we set, walk you through what they mean, and stay engaged as your needs evolve.
Recent work
Projects we've delivered
Strategy
Greater Denver, CO
Entity Restructuring for S-Corp Savings
Owner-operated business, multi-entity planning
Owner-operated business, multi-entity planning. Saved $11,400 in year one through strategic restructuring.
Saved $11,400 in year one through strategic restructuring
Implementation
the Denver metro area, CO
IRS Defense & Representation
Audit response, agent negotiation
Audit response, agent negotiation. Resolved on client's behalf; no settlement surprises.
Resolved on client's behalf; no settlement surprises
Advisory
Denver, CO
Bookkeeping System Overhaul
Messy records to clean monthly accounting
Messy records to clean monthly accounting. Tax prep time cut by half; zero scrambles at filing.
Tax prep time cut by half; zero scrambles at filing
Strategy
Greater Denver, CO
Multi-State Compliance Filing
Federal and state filings, quarterly estimated taxes
Federal and state filings, quarterly estimated taxes. On-time filing every quarter; no penalties or extension fees.
On-time filing every quarter; no penalties or extension fees
Implementation
the Denver metro area, CO
Year-Round Tax Planning Engagement
Quarterly strategy reviews, mid-year adjustments
Quarterly strategy reviews, mid-year adjustments. Owners make better business decisions knowing tax impact upfront.
Owners make better business decisions knowing tax impact upfront
Reviews
What clients say
5.0 average · 4 reviews
“Saved us $11,400 in the first year by restructuring our entity. Diane explains everything in plain English.”
J. Morrison
Denver, CO · via Google
“Clients describe Diane and her team as 'unusually patient with numbers' — small-business owners praise the plain-English explanations and same-day responses.”
A. Whitfield
Greater Denver, CO · via Google
“Known for Small-Business Bookkeeping, Federal & State Tax Filing, IRS Representation.”
M. Delgado
the Denver metro area, CO · via Google
“Diane Whitfield founded Summit in 1998 after twelve years inside Big Four audit teams. The reason was simple: small business owners were getting the same boilerplate advice as Fortune 500s.”
S. Coleman
Denver, CO · via Google
FAQ
Frequently asked questions
Do you serve out-of-state clients?
Yes — we file in all 50 states for personal and S-Corp returns.
What does ongoing bookkeeping cost?
Plans start at $325/month for businesses under $1M revenue.
Can you help with back taxes?
Yes — IRS representation and back-year filings are our specialty.
Ready to start your project?
Tell us what you have in mind and we’ll put together a clear, no-obligation estimate for Denver, Greater Denver, the Denver metro area.