The McKillip Group

What The McKillip Group does

The McKillip Group operates a small, locally-concentrated accounting and tax practice under the trade name Castle Rock Tax (formerly Castle Rock CPAs), based in Castle Rock, Colorado. Founded in 2010, the firm serves individuals and small businesses in the Colorado market with a full-scope service stack including tax return preparation, tax planning and projections, taxpayer representation (audit/dispute support), bookkeeping, payroll processing, and business consulting on structure, benefits, and acquisition readiness. Delivery is hybrid — in-person at the Castle Rock office and remote via video/phone — with a third-party secure online client portal (SecureFilePro) used for document exchange. The underlying technology is conventional accounting and payroll tooling rather than proprietary platforms; the website and client portal are built on Squarespace and a standard secure-file portal, respectively.

The firm is privately held, operates with 1–10 employees, and has no disclosed investors, funding rounds, parent company, or M&A activity. Revenue is generated primarily through fee-for-service engagements with individuals and small businesses; pricing is not publicly disclosed. Distribution relies almost entirely on a single Squarespace-hosted website, Google Reviews for social proof, and word-of-mouth referrals — there are no outbound sales motions, partnerships, or paid acquisition channels. In 2025 the firm rebranded from Castle Rock CPAs to Castle Rock Tax with the tagline "Tax Puzzle Solved," signaling a sharpening of positioning toward tax services while maintaining its existing bookkeeping, payroll, and consulting offerings. No AI/ML capabilities, APIs, patents, certifications, or third-party integrations beyond standard accounting workflows are disclosed.

Name

The McKillip Group

Website

https://castlerockcpas.com

Company type

Private

Founded year

2010

Operating status

Operating

Headcount range

1–10 employees

Short description

The McKillip Group operates Castle Rock Tax, a small Colorado-based accounting firm (founded 2010, 1–10 employees) that provides tax preparation, tax planning, bookkeeping, payroll, and business consulting services to individuals and small businesses via in-person and remote delivery.

Ownership category

akta.pro rank

Headquarters

HQ city

Castle Rock

HQ country

United States

HQ region

North America

Markets served

GTM type

B2B and B2C

Offering type

Services

Cost components

Personnel, Operations, Marketing or Sales, Technology or R&D

Distribution channels1 record

Marketing channels3 records

Core offering

The McKillip Group (doing business as Castle Rock Tax) is a Colorado-based accounting firm that provides tax return preparation, tax planning and projections, taxpayer representation before the IRS, ongoing bookkeeping, payroll processing, and business consulting for individuals and small businesses. Engagements are delivered via a combination of in-person office meetings in Castle Rock and remote video/phone consultations, with an online client portal used for secure document exchange.

Product overview

Castle Rock Tax offers a unified suite of accounting and tax services for individuals, small businesses, and their owners. The core service portfolio includes Tax Return Preparation, Tax Planning & Projections, Taxpayer Representation, Bookkeeping Services, Payroll, and Business Consulting. The firm also provides a Client Portal as an add-on service enabling secure document exchange. The company rebranded from Castle Rock CPAs to Castle Rock Tax, and serves clients in Colorado since 2010.

Differentiator

Problem solved

Functional benefit

Products and services

• Tax Return Preparation

Segments1 record

Ideal customer profiles1 record

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Recent moves2 records

Expansion highlights3 records

Direct peers

• Jackson Hewitt: National tax preparation franchise focused on individual and small-business returns; comparable service mix (tax prep, planning, representation) and seasonal client model.
• 1-800Accountant: Virtual accounting and tax service targeting SMBs and entrepreneurs; comparable SMB-focused bundled offering (tax, bookkeeping, advisory) delivered remotely, mirroring Castle Rock Tax's remote service model.
• Padgett Business Services: Franchise network of accounting firms serving small businesses with tax, bookkeeping, payroll, and consulting — same service portfolio and same small-business ICP as Castle Rock Tax.
• Intuit TurboTax Live: Intuit's assisted tax-prep tier pairing DIY software with a live CPA or EA — directly substitutes for a small-firm tax-prep experience at scale, particularly for remote clients.
• Liberty Tax: Brick-and-mortar tax preparation franchise similar to H&R Block and Jackson Hewitt; competes for the same walk-in individual and SMB tax clients.

Broad incumbents

• CBIZ: National professional services firm offering tax, accounting, and advisory to SMBs and individuals; comparable service mix but much larger scale and geographic reach.
• H&R Block: Largest U.S. retail tax preparation chain with national retail and digital offerings; competes directly with The McKillip Group for individual and small-business tax clients, though at vastly greater scale and brand recognition.
• BDO USA Private Client & Small Business: Top-tier accounting firm with a small-business and private-client practice; overlaps with Castle Rock Tax's tax planning, return prep, and advisory offerings at the upper end of the SMB market.

Emerging players

• GreenSlate: Cloud-based payroll and accounting services for small businesses; overlaps specifically with the firm's payroll and bookkeeping offerings, viewed as a potential technological substitute.
• Bench (now Brex Accounting): Tech-enabled bookkeeping and tax service for SMBs; competes for recurring monthly bookkeeping and tax-prep work that is core to The McKillip Group's service portfolio.

Market position

Strengths3 records

Weaknesses3 records

Competitive moat2 records

Key risks5 records

Key highlights5 records

Customer concentration

• Facebookfacebook.com/The-McKillip-Group-CPAs-456865930993479
• LinkedInlinkedin.com/company/the-mckillip-group-inc.

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about The McKillip Group